Sensors and Actuators B: Chemical · most nanomaterial synthesis methods can hardly realize the large-scale preparation of nanomaterials on electrode due...

A

ZSC

a

ARR1AA

KSNSN

C

1

bahyb

h0

Sensors and Actuators B 243 (2017) 919–926

Contents lists available at ScienceDirect

Sensors and Actuators B: Chemical

journa l homepage: www.e lsev ier .com/ locate /snb

dvanced nanomaterial inks for screen-printed chemical sensors

henyu Chu, Jingmeng Peng, Wanqin Jin ∗

tate Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, College ofhemical Engineering, Nanjing Tech University, 5 Xinmofan Road, Nanjing 210009, PR China

r t i c l e i n f o

rticle history:eceived 10 May 2016eceived in revised form4 November 2016ccepted 4 December 2016vailable online 5 December 2016

a b s t r a c t

Screen-printing technology is an efficient integrated preparation method for the manufacture of chemicalsensors in biological detection due to its low cost, large scale capacity and facile operation. Especially withthe fast development of the nanomaterial science, more and more nanomaterials have been introduced inthe fabrication of screen-printed chemical sensor devices. Among them, most research just focuses on themodification of nanomaterials on the already screen-printed electrode. However, if the nanomaterial can

eywords:creen-printed chemical sensorsanomaterial inksynthesis methodsanostructure protection

be directly prepared as the screen-printing ink, the efficiency will be greatly improved due to the processsimplification and cost reduction. In this review, the recent progress in the nanomaterial based inks forscreen-printed chemical sensors will be summarized, especially emphasizing the nanostructure synthesisand protection methods for the ink preparations. The performance of different nanomaterial inks printedchemical sensors are concluded with the different applications, the theoretical work mechanisms ofdifferent nanomaterials are also discussed for comparison.

© 2016 Elsevier B.V. All rights reserved.

ontents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9192. Nanomaterial based screen-printing inks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 920

2.1. Noble metal nanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9202.2. Carbon based nanomaterials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9212.3. Other inorganic materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9212.4. Nanostructured conductive polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 922

3. Applications for biological analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9243.1. Effects of screen-printing configuration on the performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9243.2. Applications of different nanomaterial printed chemical sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 924

4. Conclusions and future perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 924Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 925References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 925Biography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 925

. Introduction

Clark and Lyon [1] developed the first generation of enzymaticiosensor for blood sugar detection, and this research field has

been transferred to commercial products for real applications [5–7].There are many reasons that hinder chemical sensor technologytransfer from the laboratory to industrial products. One is unsat-isfactory performance of the prepared sensors, and another is

ttracted increasing interest due to its close relation with humanealth [2–4]. Although various chemical sensors for biological anal-sis are emerging with the progress of technology and theory iniology, chemistry, materials, and other areas, few devices have

∗ Corresponding author.E-mail address: [email protected] (W. Jin).

ttp://dx.doi.org/10.1016/j.snb.2016.12.022925-4005/© 2016 Elsevier B.V. All rights reserved.

limitations of the fabrication method for large scale manufactureat low cost.

In early research, chemical sensor performance was consideredto be determined mainly by the innate properties of electrode
materials. Therefore, research mainly focused on selection of suit-able material for sensor fabrication [8–11], and synthesis of newor composite sensing materials became a key research focus.However, with the recent development of nanoscience, above con-

920 Z. Chu et al. / Sensors and Actuat

ctomndiwrod

rdafu

nggntftascveHbseitiadekpiardts[estac

chemical interaction.Tangkuaram et al. [49] applied a chitosan solution to disperse

Fig. 1. Schematic of the work principle for screen-printing technology.

ept are changing. More and more researches have demonstratedhat, besides of electrode material properties, the nanostructuref electrode materials can also strongly affect the sensing perfor-ance, such as sensitivity, selectivity, and stability [12–15]. Regular

anostructure with uniform distribution can remarkably improveetection performance compared with disordered structures. This

s mainly attributed to its high crystallinity and large contact areahich possesses more catalytic sites and low electron transfer

esistance [16–18]. Thus, innate properties and the nanostructuref the sensing material are now both considered critical for finalevice performance.

However, most nanomaterial synthesis methods can hardlyealize the large-scale preparation of nanomaterials on electrodeue to their limits. Therefore, many research outcomes are not suit-ble for bulk product manufacture. What is strongly needed is aacile method to realize large scale preparation of chemical sensorssing nanomaterials.

Screen-printing is a stencil printing method [19–21] that wasot popularized until the silk screen was developed [22], whichreatly improved printing quality and control. Fig. 1 shows theeneral principle for screen printing. A screen is the core compo-ent to produce the designed pattern. A substrate is placed underhe screen, and ink is dropped on a blank area of the board awayrom the pattern. A scraper pushes the ink to cover the whole pat-ern region. The ink transfers through the screen openings, anddheres on the substrate. After drying, the pattern is printed on theubstrate. However, many parameters can affect the printing pro-ess, such as ink composition, screen count, scratching force, inkiscosity, etc. [23]. In mature industrial productions, these param-ters have already been studied and addressed for normal printing.owever, research has become focused on the development ofiosensing materials for screen printing. The simplest biologicalensing material is enzyme. Due to the unsatisfactory viscosity ofnzyme solution, carbon ink is normally mixed as the ink for print-ng working electrode. This preparation method was developed inhe early research of screen-printed chemical sensors. Till now, var-ous enzymes have been applied to prepare this type of inks, suchs horseradish peroxidase and glucose oxidase [24], lactate oxi-ase [25], CYP450 2B4 [26] and so on. Although this preparation ofnzymatic ink is facile, the work electrode which is printed by thisind of enzyme-only ink without other catalytic materials cannoterform superior sensing function due to the low catalytic activ-

ty. In recent years, due to advanced function and cost reduction,n increasing number of nanomaterials have been adopted for fab-ication of various screen-printed chemical sensors for biologicaletections [27–29], and the technology has realized accurate con-rol of printed film thickness to several micrometers. Many of theseensors exhibit stable and reliable performance for food inspection30], clinical diagnosis [31], pollution monitoring [32], etc. How-ver, these applications generally apply nanomaterials on alreadycreen-printed electrodes, rather than modifying the ink prepara-
ion [33–37]. Compared with direct application of nanomaterialss the printing ink, this preparation route requires more steps andhemicals, increasing the fabrication cost and time, as well as suf-
ors B 243 (2017) 919–926

fering from relatively poor adhesion between the applied materialsand screen-printed electrode.

Another common strategy is the preparation of enzyme con-taining inks for screen-printing, so that biological material issimultaneously deposited with the printed sensing material. Glu-cose oxidase [38], acetylcholinesterase [39], lactate dehydrogenase[40], tyrosinase [41], and many other enzymes [42] have beenmixed with sensing inks for screen-printing. This method canshorten the preparation procedure, but generally the sensing nano-material cannot retain its regular shape and uniform distributiondue to strong aggregation of the enzyme molecules. Recentlyresults have confirmed the possibility of direct preparation of thenanomaterial ink for screen-printing. However, there has beenno review to summarize the available nanomaterials as screen-printing ink for chemical sensor fabrication, although they haveshown promise for the transfer from laboratory to industry.

Therefore, this review discusses the newly developed nanoma-terials as printing inks for screen-printed chemical sensors. Thematerials are classified by their chemical compositions, and incontrast to reviews of screen-printed chemical sensors, we giveemphasis to ink synthesis methods for nanostructured materials,as well as nanoscale morphologies, and address the key issue of pro-tecting the material nanostructures during ink preparation. Finally,we compare the performance of screen-printed sensors fabricatedusing nanomaterial inks. Thus, we provide an overview of nano-materials and related progress for fabrication of screen-printedchemical sensors, providing suggestions for material selection forink preparation. This summary of the state of the art also highlightscurrent and potential research areas for further development ofnanomaterial based chemical sensors using screen-printing tech-nology.

2. Nanomaterial based screen-printing inks

Although many nanomaterials have been developed for prepa-ration of chemical sensors, few can be directly applied asscreen-printing inks. To obtain suitable nanomaterial inks, ex-situnanostructure synthesis is required. Solution dispersed nanoma-terial is preferred due to facile adjustment of viscosity by drying.Otherwise, additives are required for solid state materials toensure dissolution. However, during drying or dissolution, thenanostructured particles tend to have strong agglomeration, lead-ing to significantly decreased performance and uneven printing.Therefore, designing appropriate nanostructure synthesis methodsincorporating the different material properties is the key problemto ink preparation.

2.1. Noble metal nanoparticles

Because of their high catalysis and conductivity, noble metalswere employed from very early in the development of chemi-cal sensor preparation [43–45]. However, their nanostructures aremostly provided by in-situ synthesis methods (such as electrode-position [46], chemical vapor deposition [47], and hydrothermalsynthesis [48]) on the substrate, which makes them in appro-priate for screen-printed electrode fabrication. The difficulty ofex-situ approaches is prevention of over-aggregation of noblemetal nanoparticles in the solution. Fig. 2 shows a potentialapproach to solve this problem for ink preparation by introduc-ing extra substances to disperse nanoparticles with physical or

synthesized Au nanoparticles. Homogeneous 16.8 nm Au particleswere first prepared by Na-citrate reduction of HAuCl4 solution.Then this suspension solution was mixed with the chitosan solution

Z. Chu et al. / Sensors and Actuators B 243 (2017) 919–926 921

nanop

aUlhert

ssslutdcLtTs

vomtit

2

teiiaoargcea

pMi

Fig. 2. Preparation of noble metal

s the deposition ink to effectively avoid nanoparticle aggregation.V–vis spectra confirmed that the small Au nanoparticles produced

ess aggregation after bonding to the biomolecule. For application,orseradish peroxidase was further modified on the carbon worklectrode for H2O2 detection. The resulting H2O2 sensor showedemarkable storage stability, maintaining 95% current response upo 30 days.

Another nanostructured Ag suspension ink was developed forcreen-printing by Cho et al. [50]. A 20 nm Ag nanoparticle suspen-ion was prepared by reduction between AgNO3 and formaldehydeolutions, and polyvinyl pyrrolidone (PVP) was applied as a stabi-izer to avoid aggregation. However, the suspension viscosity wasnsuitable for printing, and the solution purity was inferior. Ace-one was used to remove PVP, and diethylene glycol was added andried to adjust the suspension viscosity. Inks with different silveroncentrations were prepared for comparison of printing effects.ower silver concentrations (<60%) were unable to produce con-inuous patterns, which was attributed to unsatisfactory viscosity.he screen count was also investigated, and confirmed that highercreen hole counts produced more exact printed patterns.

Thus, noble metal nanoparticles in solution or colloid can pro-ide sufficient structural stability, and the introduction of stabilizerr reactant with metals before ink preparation has become the mainethod to protect nanoparticle shape and size. However, due to

heir high cost and unstable storage, nanostructured noble metalnks are not widely applied in either research or industrial produc-ion.

.2. Carbon based nanomaterials

Carbon materials, including graphite, graphene, carbon nano-ubes (CNTs), and their derived materials, have been widelymployed as biosensing materials due to their superior conductiv-ty [51–53]. Resin mixed graphite powder is often used as carbonnk for fabrication of screen-printed electrode [54], and worknd counter electrodes of commercial screen-printed chips areften prepared using carbon ink. However, these chips are mainlydopted as substrates for further modification of biosensing mate-ials on the work electrode due to the weak catalytic activity ofraphite and resin, and are rarely used for direct application ofarbon ink for sensing. On the contrary, although the compositionlement is same, CNTs and graphene have quite different structures
nd are commonly employed as biosensing materials [55].
Multi-wall carbon nanotube (MWCNT) has been used as screen-rinting ink for construction of glucose biosensors [56]. The purifiedWCNT powder was ground to fine particles, and then mixed with

sophorone solution containing polyvinyl chloride, dimethyl succi-

article based screen-printing ink.

nate, and dimethyl glutarate to form a homogeneous ink. Aluminaceramic plates were used as screen-printing substrates. The inkexhibited good tolerance to mechanical abrasion as well as excel-lent adhesion on the ceramic substrate. More importantly, MWCNTink prepared electrodes showed very low resistance. Fabregas et al.[57] also employed MWCNT as the main component for screen-printing ink, using polysulfone (PS) as the solvent. They producedmulti-layered screen-printed electrodes with, from the bottom totop, polycarbonate substrate, silver, carbon, and MWCNT/PS layers.The authors did not explain the reason for the complex layer struc-ture, but the introduction of silver and carbon layers can definitelyimprove electrode conductivity. They used their nanomaterial inkto prepare an enzymatic biosensor and immunosensor, and thesingle-walled CNT ink can currently be purchased commercially.

Since the 2004 Noble Prize was awarded, preparation and appli-cation of various graphene materials have been applied in manyscientific areas [58], and its excellent conductivity and biocompat-ibility [59] are greatly attractive for chemical sensor. Accordingly,graphene based screen-printing inks have been studied for fab-rication of biosensing chips. Ying et al. [60] synthesized graphiteoxide from graphite powder, and then obtained reduced grapheneoxide (rGO) by ultrasonication and hydrazine reduction reaction byturns. To adjust the viscosity, they added cellulose acetate, cyclo-hexanone, and acetone as the solvent. After sufficient ultrasonictreatment, a homogeneous viscous ink with ca. 200 nm rGO sheetswas harvested (Fig. 3a). Without the assistance of other catalyticmaterials, rGO-only printed electrodes exhibited low transfer resis-tance and excellent oxidation activity for simultaneous detection ofascorbic acid, dopamine, and uric acid from the different potentials(Fig. 3b). Karuwan et al. [61] developed a graphene-carbon pasteink by a home-made method. After synthesis of graphene powderfrom graphite, they simply added the powder to commercial carbonpaste ink to prepare the screen-printing ink. They investigated theeffects of graphene content on the electrochemical performance,and showed that 10 wt% was the optimum condition. However,microscopic characterization confirmed the heterogeneous distri-bution of graphene and graphite particles using this method.

Although carbon nanomaterial inks can be produced by mix-ture with commercial carbon ink or polymers, low catalytic abilityis always an obstacle for preparation of high performance screen-printed chemical sensor. The relatively high cost may be anotherfactor hindering large scale production for screen-printing. Its fur-
ther application should be considered for promoting conductivityfor synthesis of other material based inks.

922 Z. Chu et al. / Sensors and Actuators B 243 (2017) 919–926

F ) CycP M ur

2

mdo

nciicis

A

P

H

wot

r[tabclmo

taatps

tlaomsla

ig. 3. (a) SEM image of rGO based ink (inset: tapping-mode AFM image of rGO); (bBS (pH 7.0) containing 1.0 mM ascorbic acid (AA), 1.0 mM dopamine (DA) and 1.0 m

.3. Other inorganic materials

Aside from noble metal and carbon materials, many inorganicaterials have been prepared as screen-printing inks, such as coor-

ination complexes and metal oxides. We provide an introductionf some typical nanomaterials in these categories.

Prussian blue (PB, Fe4[Fe(CN)6]3) is a classic inorganic coordi-ation complex [62], with only three elements, iron, nitrogen andarbon, comprising its cell structure (Fig. 4a), where neighboringron atoms have different valances (+3 and +2). It shows outstand-ng electrochemical redox behavior for catalysis of H2O2, and hencean be applied for preparation of various chemical sensors aftermmobilization of different oxidases [63] (Fig. 4b). The commonensing mechanism can be explained as follows:

oxidase(A)→ Aox + H2O2 (1)

B + e → PW (2)

2O2 + PW → PB + 2OH− (3)

here A represents the bio-target, oxidase (A) means the matchingxidase of A, PB is the Prussian blue molecule, and PW representshe reduced PB state.

PB has a large family of analogues, with the different Fe atomseplaced by other metal elements, such as Co, Ni, Mn, Cr, etc.64]. The analogues retain the face-centered cubic structure, andheir formation reactions are also similar using the metal cationnd metal cyanide anion. Different analogues provide differentiosensing functions. However, PB and its analogues cannot be wellontrolled for nanostructure formation because of their fast crystal-ization rate. Accordingly, development of a nanostructure control

ethod for PB ink could provide a versatile strategy for fabricationf PB (and analogues) based sensor devices.

Our group has concentrated much effort on nanostructure con-rol of PB film and its biosensor applications, with many facilepproaches developed, such as electrostatic self-assembly [65],erosol deposition [66,67], electric field induced self-assembly [68],emplate assisted self-assembly [69], etc. Recently, to realize deviceroduction of PB biosensors, we designed an original route for largecale synthesis of PB nanostructured ink [70].

As discussed above, the difficult structural control is attributedo the fast formation rate of PB crystals. To reduce crystal-ization and aggregation rates, a low speed chemical synthesispproach was developed. Two reaction solutions were simultane-
usly injected into a high volume water container by a low speedotor, with average injection rate 0.5 ml/min. The resultant PB
uspension was composed of numerous very uniform and regu-ar nanocubic crystals (Fig. 4c). After drying and adding carbon ink,

viscous dark blue ink was obtained. The resulting printed biosen-

lic Voltammetry (CV) diagrams for (i) graphite ink and (ii) rGO ink sensors in 0.1 Mic acid (UA). Reproduced from Ping et al. [60], with permission from Elsevier.

sor chips (Fig. 4d and e) exhibited high sensitivities in detection ofglucose, lactate, and glutamate by the respective immobilizationsof glucose, lactate, and glutamate oxidases. Its detection of bloodglucose was also demonstrated to be very close with the real con-tent. Without specificity, this method is promising for preparationof PB analogue based screen-printed biosensors.

ZnO is a popular semi-conductor, and widely applied in the fab-rication of optical, magnetic and electrochemical sensors [71]. Itsband gap between the lowest unoccupied molecular orbital (LUMO)and highest occupied molecular orbital (HOMO) is approximately3.24 eV at 300 K [72]. Therefore, it normally requires high energyfor excitation of conduction band electrons. However, due to incor-porating existence oxygen, it possesses the detection advantage ofoxidizing the bio-target. The biosensing behavior of ZnO is typical ofmost of metal oxides, and ZnO based chemical sensors can provideanalysis of glucose, uric acid, cholesterol, etc. [73,74]. Its abundantnanostructures also provide research opportunities for material sci-ence. Nanorod, nanowire, nanoflower, and nanocomb ZnO filmshave been synthesized by hydrothermal, electrodeposition, andultrasonication methods [69]. For screen-printing applications, Qiet al. [75] prepared a flower-like ZnO nanorod based ink. Theflower-like ZnO nanorod powder was synthesized using a chem-ical baths method. Zn(OH)2 was used as the precursor and thedissolution–reprecipitation reaction produced ZnO nanorods. Thispowder was further ground and diluted with water to a paste fordirect printing.

Another synthesis strategy was developed using ZnO nanowires[76]. ZnO nanowires were prepared from zinc nitrate hexahydratesolution. A hexamethylenetetramine solution was then added andheated to 90 ◦C for 3 h. ZnO was extracted and dried to form apowder and subsequently mixed with commercial carbon paste toproduce screen-printing ink. Thus, to synthesize nanostructuredZnO ink, one must first synthesize the powder, and then mix thiswith water or solvent to adjust the viscosity. This is probably dueto the very weak solubility of metal oxides. Although the synthesisreaction begins in solution, the formed crystal is easily precipitatedout of the suspension. Directly using the reacted product will resultin non-uniform distribution of nanocrystals. Therefore, fine powderis produced by drying and grinding.

Similar to ZnO, many other metal oxide nanocrystals have beenused for as screen-printing inks, such as bismuth oxide, tin-dopedindium oxide, �-manganese oxide, etc. [77–79]. The nanostruc-tured metal oxides normally possess high catalysis, particularly foroxidation, but the high band gap and weak conductivity may be an
issue for sensing performance.


Fig. 4. (a) Structure of a PB unit cell; (b) work mechanism of PB based biosensors; (c) nanostructure of the PB ink by low speed chemical synthesis; (d) screen-printedbiosensor chip using PB nanocube ink; (e) EDX scanning of iron in the printed working electrode surface. Reproduced from Jiang et al. [70], with permission from Elsevier.

F r confi

2

mlboosdp

ciagha

ccpupmw

ig. 5. (a) Screen printed sensor chip with six configurations; (b) structure details fo

.4. Nanostructured conductive polymers

Compared with polymers, inorganic materials normally possessuch higher catalysis and conductivity. However, polymer mal-

eability and plasticity is superior. Polymer was long believed toe unable to conduct due to strong resistance caused by the longrganic chain. However, this concept was changed with synthesisf conductive polypyrrole (PPy) in 1978 by IBM. Subsequently, aeries of conductive heterocyclic and benzene polymers have beeneveloped and applied for chemical sensor fabrications, includingolyaniline (PANi) and polythiophene [80].

The molecular weight and viscosity of these materials can beontrolled to satisfy the requirements of screen-printing ink, andmportantly, the printed electrode can exhibit excellent bendingbility and light weight, which is a significant difference from inor-anic materials. In recent decades, nanosize control technologiesave been introduced in fabrication of nanostructured polymers,nd some have produced nanostructured polymer inks for printing.

PPy has been widely used in the fields of battery, sensor andapacitor due to its good conductivity which arises from its �-onjugated backbone structure [81]. PPy is normally obtained byolymerization of pyrrole (Py) monomer. Yawale et al. [82] contin-
ously added Py monomer into FeCl3/methanol solution to realizeolymerization by the increasing oxidation potential, attributed toethanol evaporation. After purification, 60 wt% PPy was mixedith butyl carbitol and ethyl cellulose to prepare the paste ink. SEM
guration 1. Reproduced from Tangkuaram et al. [46], with permission from Elsevier.

characterization showed that the printed electrode surface had ananosized honeycomb-like structure, and this structure also canbe adjusted by controlling the Py/FeCl3 ratio.

Subsequently, PPy ink has been developed for preparation ofwholly printed biosensors [83]. Although this ink was used ininjecting printing, its application is promising to extend to screen-printing. PPy was also obtained by polymerization from Py, but thecomposition of the reaction solution included polyvinyl alcohol andgemini surfactant with oxidants of p-toluenesulfonate hexahydrateand FeCl3. This polymerization route required quite long (24 h)reaction times and more than 64 h for purification. For the con-struction of biosensors, enzymes, including horseradish peroxidaseand glucose oxidase, were mixed into PPy to prepare PPy/enzymeinks for printing. SEM images showed the prepared inks had verysmall nanoparticles covered by enzymes. The printed electrodeprovided fast response and stability in detection of H2O2 and glu-cose. The substrate was flexible polyethylene terephthalate, withgood blending and folding capacity.

PANi itself is an insulator, but can become conductive withincorporation of salts or surfactants due to protonation of itsimine nitrogens. Conductivity can exceed 100 S/cm with intro-duction of toluenesulfonamide during polymerization [84]. Some
printed PANi inks have included nanostructures. Direct applica-tion of synthesized PANi for screen-printing is unsuitable due tostrong particle aggregation which can block the screen. There-fore, Gill et al. [85] applied 10 wt% polyvinyl butyral as binder,

9 ctuat

1PT3aisawd

piseewppmdopieitsv

tIcef

3

3

ddnc

scmec(tCtwipobhtbgs

24 Z. Chu et al. / Sensors and A

0 wt% PS3 surfactant as blocking agent, to prevent aggregation ofANi nanoparticles, and ethyleneglycolmonobutylether as solvent.he thickness of the resulting PANi film can be controlled within5 �m, and provides very low electrical resistance. The authorslso prepared a PANi film by direct drop deposition for compar-son, and found the resistance was at least 103 times that of thecreen-printed film. Screen-printing compressed the nanoparticlesnd provided a connected electron path, decreasing the resistance,hereas drop deposition tended to produce cracks and vacancies

uring drying which blocked electron transfer.Poly(3,4-ethylenedioxythiophene) (PEDOT), a derivative of

olythiophene, is one of the most popular conductive materialsn biosensor fabrication, and has been demonstrated to possessuperior conductivity to PPy [86]. Its positive charge is also ben-ficial for enzyme immobilization and electron transfer due tolectrostatic interaction. However, PEDOT solubility is very weak,hich hinders uniform distribution of nanoparticles in screen-

rinting ink. To solve this problem, Istamboulies et al. [84] appliedoly(styrenesulfonate) (PSS) as electrolyte during the PEDOT for-ation reaction. Ethylenedioxythiophene (EDOT) and PSS were

issolved together in water with continuous drop-wise additionf ammonium peroxydisulphate. The polymerization reaction wasrocessed ultrasonically for one hour, and a dark blue aqueous

nk was obtained that could be directly printed as the workinglectrode. Conductivity of prepared electrode was enhanced withncreasing PEDOT ratio, reaching 2420 S/cm for 100% PEDOT. Afterhe immobilization of acetylcholinesterase, the work electrodehowed high oxidation ability to the choline at the potential 100 mVs. Ag/AgCl.

The nanostructure of conductive polymer based ink is difficulto control, and normally produce irregular nanoparticle placement.n contrast to inorganic materials, polymers don’t have a redoxenter, and consequently their catalysis performance is weak. How-ver, the pliability of their printed products is promising to developabrication of portable miniature chemical sensor devices.

. Applications for biological analysis

.1. Effects of screen-printing configuration on the performance

Screen-printing is a convenient large scale method for pro-uction of chemical sensor chips, and many sensors have beeneveloped, particularly electrochemical sensors. The structure isormally constructed by screen-printing a three electrode systemomposed of working, counter, and reference electrodes.

However, there is no criterion for the screen pattern whencreen-printing the chemical sensor. Therefore, the reported sensorhip configuration performance vary for different designs, whichay influence the sensing performance. Tangkuaram et al. [54]

xamined the performance of chemical sensor chips with differentonfiguration, as shown in Fig. 5a. They used cyclic voltammetryCV) characterizations to investigate the reversibility and conduc-ivity of six chips prepared using the same electrode materials.onfiguration 5 showed possessed the best electrochemical sensi-ivity and reversibility, attributed to the largest counter electrode,hich can promote rapid transfer of large quantities of ions dur-

ng the sensing process. Configuration 1 chips produced redoxeaks, but no obvious signal change with increasing concentrationf K3Fe(CN)6. Configuration 2 chips had the reference electrodeetween the work and counter electrodes, and these produced
igh current errors for repeated experiments. The authors explainhat electron transfer between work and counter electrodes waslocked by the reference electrode. The other three chips showedood performance, but inferior to configuration 5 chip due tomaller counter electrodes. Thus, the screen-printed configuration
ors B 243 (2017) 919–926

made a significant difference to the sensor chip performance, andoptimal results were for larger counter electrode, and locating thereference other than between the working and counter electrodes.

3.2. Applications of different nanomaterial printed chemicalsensors

The analysis of physiological index is essential for clinic eval-uation of health status. Due to the complex composition of bloodor body fluid, different chemical sensors are required to recognizethe different targets. Chemical sensors screen-printed from nano-material inks have been successful applied in detection of variousphysiological substances.

For a given configuration, the detection target and performanceare largely determined by the printed material properties on theworking electrode. Many nanomaterials have been synthesized asinks for fabrication of screen-printed chemical sensors, as summa-rized in Table 1.

Most research on screen-printed chemical sensors used glucoseas the detection target for performance evaluation. Glucose oxidasemust be immobilized on the prepared working electrode to oxidizeglucose for generation of a response signal (current or potential).During this process, the main functions of the printed nanomateri-als are signal magnification by electrocatalysis and signal transferby conductivity. Thus, these material properties are for sensing per-formance, particularly sensitivity. However, comparing the listedglucose sensors (Table 1), nanomaterial electrocatalysis seems tobe the most important factor.

Nanostructured silver and PB, which have superior catalyticactivity, are beneficial to promote sensitivity. PB is called artifi-cial peroxidase due to its remarkable catalysis for H2O2. Therefore,although silver has higher conductivity than PB, which is a semi-conductor [96], the sensitivity of PB nanocubes still exceeds that ofAg nanoparticles. Most other materials show much lower perfor-mance. Aside from PbO2 and cobalt phthalocyanine, screen-printedchemical sensors can be operated under negative potential to pro-vide good selectivity.

PB can be applied for detection of various physiological targetsafter immobilizations of different oxidases. As shown in Table 1,PB nanocube ink printed chemical sensors also exhibit high perfor-mance for analysis of lactate and glutamate at low concentrations.This nanomaterial ink and preparation route can be extended topreparation of other chemical sensors for analysis of more sub-stances.

Following glucose detection, many other applications have beenalso realized by chemical sensors with various nanomaterial inks,such as detections of dopamine, hCG Hormone and pesticide. Thesereported results show these sensors have good detection perfor-mance. We believe this trend will only accelerate and many morenanomaterials will be adopted for ink preparation for sensing ofphysiological substances.

4. Conclusions and future perspectives

We have summarized typical nanomaterials that have been usedas inks for direct fabrication of screen-printed chemical sensors,as well as the strategies for their nanostructure synthesis and inkpreparation. The resulting sensors exhibit very high performancedue to strong catalysis or conductivity attributed to the nanos-tructured materials. Their applications have extended to clinical
diagnosis, food safety, and pollution monitoring. Some chemicalsensor devices have also been fabricated to provide real-time detec-tion. Only a very small subset of nanomaterials has been studied forpotential screen-printing chemical sensors, exhibiting advancedperformance and potential industrial production. These achieve-


Table 1Chemical sensors screen-printed by the nanomaterials based inks.

Material Nanostructure Application Potential (V) Sensitivity Limit of detection Linear arrange Ref.

Gold Nanoparticle H2O2 −0.4 0.176 �A mM−1 10 �M 0.01–11.3 mM [49]CNT/PS Nanoparticle/ Nanotube H2O2 −0.2 0.12 �A mM−1 25 �M 0.02–0.5 mM [57]PPy Nanoparticle H2O2 −0.2 1.42 �A mM−1 10 �M 0.01–10 mM [80]Silver Nanoparticle Glucose −0.05 20.09 �A mM−1 cm−2 – 0-2.6 mM [88]Lead oxide Nanoparticle Glucose 0.7 0.183 �A mM−1 – 0–10 mM [89]PB Nanocube Glucose −0.05 83.404 �A mM−1 cm−2 10 �M 0.01–1.3 mM [70]Cobalt phthalocyanine Nanoparticle Glucose 0.5 1.12 �A mM−1 200 �M 0.2–5 mM [90]PPy Nanoparticle Glucose −0.2 0.21 �A mM−1 cm−2 – 1–5 mM [85]CNT Nanotube Glucose 0.1 30 nA mM−1 (calculated) – 0–8 mM [56]PB Nanocube Lactate −0.05 6.379 �A mM−1 cm−2 10 �M 0.01–0.5 mM [70]PB Nanocube Glutamate −0.05 31.642 �A mM−1 cm−2 10 �M 0.01–1 mM [70]Graphene Nanosheet Ascorbic acid −0.05 31.4 �A mM−1 0.95 �M 4–4500 �M [60]Graphene Nanosheet dopamine 0.15 86.7 �A mM−1 0.12 �M 0.5–2000 �M [60]Graphene Nanosheet Uric acid 0.3 61.3 �A mM−1 0.2 �M 0.8–2500 �M [60]PEDOT:PSS Nanoparticle Chlorpyrifos-oxon 0.15 7.14 nA nM−1 (calculated) 4.4 �M – [87]MWCNT/PSf Nanotube hCG Hormone −0.4 4 nA mL mIU−1 14.6 mIU mL−1 0–600 mIU mL−1 [91]

−0. −1

0

−0.–

mp

Tatpbnwtc

A

TI2eAt

R

[[[

[

[

[[[

[

[[

[[[

[[[

[

[[

[[

[

[[

[

[[

[

[[[

[[

[

[

[

[

[

[

[

PEDOT:PSS Nanoparticle Bisphenol A

Cobalt phthalocyanine Nanoparticle organophosphate pesticideAu-TiO2 Nanoparticle hexavalent chromium

CNTs/Cu(II) doped CP-DDS Nanotube Sodium alkylsulfate

ents will encourage development of more nanomaterials for higherformance screen-printing inks for sensor fabrication.

However, some problems remain, and require further research.he main challenge is protection of the nanostructure withoutggregation during ink preparation. The present method is addi-ion of stabilizer agents before viscosity adjustment by mixture ofolymers or commercial carbon paste. However, most current sta-ilizers have weak conductivity or catalysis, which reduces the finalanomaterial performance. Development of suitable stabilizersith nanostructure protection but strong catalysis and/or conduc-

ivity will accelerate the transfer from nanomaterial research toommercial manufacture of chemical sensor device.

cknowledgements

This work was financially supported by the Innovative Researcheam Program by the Ministry of Education of China (No.RT13070), the National Natural Science Foundation of China (Nos.1490585, 21476107, 21406107), the Jiangsu Province Natural Sci-nce Foundation for the Youth (No. BK20140931) and Top-notchcademic Programs Project of Jiangsu Higher Education Institu-

ions (TAPP).

eferences

[1] L.C. Clark, C. Lyons, Ann. N.Y. Acad. Sci. 102 (1962) 29–45.[2] J. Wang, Chem. Rev. 108 (2008) 814–825.[3] M. Mehrvar, M. Abdi, Anal. Sci. 20 (2004) 1113–1126.[4] J. Wang, Analyst 130 (2005) 421–426.[5] M. Rhemrev-Boom, J. Venema, G. Urban, P. Vadgama, Biosens. Bioelectron. 16

(2001) 839–847.[6] L. Terry, S. White, L. Tigwell, J. Agric. Food Chem. 53 (2005) 1309–1316.[7] B. Malhotra, A. Chaubey, Sens. Actuators B 91 (2003) 117–127.[8] V. Lin, K. Motesharei, K. Dancil, M. Sailor, M. Ghadiri, Science 278 (1997)

840–843.[9] A. Karyakin, O. Gitelmacher, E. Karyakina, Anal. Chem. 67 (1995) 2419–2423.10] R. Russell, M. Pishko, Anal. Chem. 71 (1999) 3126–3132.11] B. Wang, B. Li, Q. Deng, S. Dong, Anal. Chem. 70 (1998) 3170–3174.12] A. Wanekaya, W. Chen, N. Myung, A. Mulchandani, Electroanalysis 18 (2006)

533–550.13] F. Balavoine, P. Schultz, C. Richard, V. Mallouh, T. Ebbesen, C. Mioskowski,

Angew. Chem. Int. Ed. 38 (1999) 1912–1915.14] W. Yang, K. Ratinac, S. Ringer, P. Thordarson, J. Gooding, F. Braet, Angew.

Chem. Int. Ed. 49 (2010) 2114–2138.
15] J. Chen, Y. Miao, N. He, X. Wu, S. Li, Biotech. Adv. 22 (2004) 505–518.16] L. Zhang, Q. Zhang, X. Lu, J. Li, Biosens. Bioelectron. 23 (2007) 102–106.17] C. Padeste, S. Kossek, H. Lehmann, C. Musil, J. Gobrecht, L. Tiefenauer, J.
Electrochem. Soc. 143 (1996) 3890–3895.18] P. Solanki, A. Kaushik, V. Agrawal, B. Malhotra, NPG Asia Mater. 3 (2011)

17–24.

[[[

[

15 55 �A mM 0.16 mM 0.2–8 mM [92]0.4 nA mM−1 1 nM 1–1000 nM [93]

2 11.88 �A �M−1 0.01 �M 0.01–100 �M [94]– 0.25 �M 1 �M–10 mM [95]

19] M. Tudorache, C. Bala, Anal. Bioanal. Chem. 388 (2007) 565–578.20] M. Albareda-Sirvent, A. Merkoci, S. Alegret, Sens. Actuators B 69 (2000)

153–163.21] M. Li, Y. Li, D. Li, Y. Long, Anal. Chim. Acta 734 (2012) 31–44.22] G. Dubey, Microelectron. Reliab. 13 (1974) 203–207.23] H. Goldberg, R. Brown, D. Liu, M. Meyerhoff, Sens. Actuators B 21 (1994)

171–183.24] J. Wang, P.V.A. Pamidi, D.S. Park, Anal. Chem. 68 (1996) 2705–2708.25] A.L. Hart, A.P.F. Turner, Biosens. Bioelectron. 11 (1996) 263–270.26] L. Asturias-Arribas, M.A. Alonso-Lomillo, O. Domínguez-Renedo, M.J.

Arcos-Martínez, Talanta 105 (2013) 131–134.27] K. Kerman, M. Saito, E. Tamiya, S. Yamamura, Y. Takamura, Trac-Trend Anal.

Chem. 27 (2008) 585–592.28] A. Chen, S. Chatterjee, Chem. Soc. Rev. 42 (2013) 5425–5438.29] Z. Taleat, A. Khoshroo, M. Mazloum-Ardakani, Microchim. Acta 181 (2014)

865–891.30] M. Tudorache, C. Bala, Anal. Bioanal. Chem. 388 (2007) 565–578.31] E. Crouch, D. Cowell, S. Hoskins, R. Pittson, J. Hart, Anal. Biochem. 347 (2005)

17–23.32] J. Hart, A. Crew, E. Crouch, K. Honeychurch, R. Pemberton, Anal. Lett. 37 (2004)

789–830.33] Y. Lin, F. Lu, J. Wang, Electroanalysis 16 (2004) 145–149.34] F. Arduini, M. Forchielli, A. Amine, D. Neagu, Ilaria Cacciotti, F. Nanni, D.

Moscone, G. Palleschi, Microchim. Acta 182 (2015) 643–651.35] S. Piemarini, D. Migliorelli, G. Volpe, R. Massoud, A. Pierantozzi, C. Cortese, G.

Palleschi, Sens. Actuators B 179 (2013) 170–174.36] R. Antiochia, L. Gorton, Sens. Actuators B 195 (2014) 287–293.37] N. Hernandez-Ibanez, L. Garcia-Cruz, V. Montiel, C. Foster, C. Banks, J. Iniesta,

Biosens. Bioelectron. 77 (2016) 1168–1174.38] U. Bilitewski, G.C. Chemnitius, P. Rüger, D. Schmid, Sens. Actuators B 7 (1992)

351–355.39] A.L. Hart, W.A. Collier, Sens. Actuators B 53 (1998) 111–115.40] M. Rohm, W. Genrich, U. Collier, Analyst 121 (1996) 877–881.41] J. Wang, V.B. Nascimento, S.A. Kane, K. Rogers, M.R. Smyth, L. Angnes, Talanta

43 (1996) 1903–1907.42] A.L. Hart, W.A. Collier, D. Janssen, Biosens. Bioelectron. (1997) 12645–12654.43] J. Pingarron, P. Yanez-Sedeno, A. Gonzalez-Cortes, Electrochim. Acta 53 (2008)

5848–5866.44] X. Ren, X. Meng, D. Chen, F. Tang, J. Jiao, Biosens. Bioelectron. 21 (2005)

433–437.45] H. Tang, J. Chen, S. Yao, L. Nie, G. Deng, Y. Kuang, Anal. Biochem. 331 (2004)

89–97.46] Z. Chu, Y. Liu, Y. Xu, L. Shi, J. Peng, W. Jin, Electrochim. Acta 176 (2015)

162–171.47] M. Rill, C. Plet, M. Thiel, I. Staude, G. Freymann, S. Linden, M. Wegener, Nat.

Mater. 7 (2008) 543–546.48] R. Cui, C. Liu, J. Shen, D. Gao, J. Zhu, H. Chen, Adv. Funct. Mater. 18 (2008)

2197–2204.49] T. Tangkuaram, C. Ponchio, T. Kangkasomboon, P. Katikawong, W. Veerasai,

Biosens. Bioelectron. 22 (2007) 2071–2078.50] W. Yin, D. Lee, J. Choi, C. Park, S. Cho, Korean J. Chem. Eng. 25 (2008)

1358–1361.
51] L. Shi, Z. Chu, Y. Liu, W. Jin, N. Xu, Adv. Funct. Mater. 24 (2014) 7032–7041.52] Z. Chu, L. Shi, W. Jin, Biosens. Bioelectron. 61 (2014) 422.53] Y. Liu, M. Wang, F. Zhao, Z. Xu, S. Dong, Biosens. Bioelectron. 21 (2005)
984–988.54] J. Wang, M. Pedrero, H. Sakslund, O. Hammerich, J. Pingarron, Analyst 121

(1996) 345–350.

9 ctuat

[

[[[[

[[

[

[[[[[[[

[[

[

[[

[

[[[[

[

[[

[

[

[[[

[[[

[[

[

[

[[

3 months as a collaborative visitor in 2011. He is now a lecturer at Nanjing TechUniversity. He has published over 25 internationally refereed journal papers.

26 Z. Chu et al. / Sensors and A

55] W. Guan, Y. Li, Y. Chen, X. Zhang, G. Hu, Biosens. Bioelectron. 21 (2005)508–512.

56] J. Wang, M. Musameh, Analyst 129 (2004) 1–2.57] S. Sanchez, M. Pumera, E. Cabruja, E. Fabregas, Analyst 132 (2007) 142–147.58] M. Allen, V. Tung, R. Kaner, Chem. Rev. 110 (2010) 132–145.59] Y. Shao, J. Wang, H. Wu, J. Liu, I. Aksay, Y. Lin, Electroanalysis 22 (2010)

1027–1036.60] J. Ping, J. Wu, Y. Wang, Y. Ying, Biosens. Bioelectron. 34 (2012) 70–76.61] C. Karuwan, A. Wisitsoraat, D. Phokharatkul, C. Sriprachuabwong, T. Lomas, D.

Nacapricha, A. Tuantranont, RSC Adv. 3 (2013) 25792–25799.62] H. Buser, D. Schwarzenbach, W. Peter, A. Ludi, Inorg. Chem. 16 (1977)

2704–2710.63] F. Ricci, G. Palleschi, Biosens. Bioelectron. 21 (2005) 389–407.64] A. Karyakin, Electroanalysis 13 (2001) 813–819.65] Y. Liu, Z. Chu, W. Jin, Electrochem. Commun. 11 (2009) 484–487.66] Z. Chu, Y. Liu, W. Jin, N. Xu, B. Tieke, Chem. Commun. (2009) 3566–3567.67] Z. Chu, Y. Zhang, X. Dong, W. Jin, N. Xu, J. Mater. Chem. 20 (2010) 7815–7820.68] Z. Chu, L. Shi, Y. Zhang, W. Jin, N. Xu, J. Mater. Chem. 21 (2011) 11968–11972.69] Z. Chu, L. Shi, Y. Zhang, W. Jin, S. Warren, D. Ward, E. Dempsey, J. Mater. Chem.

22 (2012) 14874–14879.70] D. Jiang, Z. Chu, J. Peng, W. Jin, Sens. Actuators B 228 (2016) 679–687.71] U. Ozgur, Y. Alivov, C. Liu, A. Teke, M. Reshchikov, S. Dogan, V. Avrutin, S. Cho,

H. Morkoc, J. Appl. Phys. 98 (2005) 041301.72] S. Ansari, M. Khan, S. Kalathil, A. Nisar, J. Lee, M. Cho, Nanoscale 5 (2013)

9238–9246.73] Z. Zhao, W. Lei, X. Zhang, B. Wang, H. Jiang, Sensors 10 (2010) 1216–1231.74] S. Arya, S. Saha, J. Ramirez-Vick, V. Gupta, S. Bhansali, S. Singh, Anal. Chim.

Acta 737 (2012) 1–21.75] Q. Qi, T. Zhang, Q. Yu, R. Wang, Y. Zeng, L. Liu, H. Yang, Sens. Actuators B 133

(2008) 638–643.76] K. Hasan, O. Nur, M. Willander, Appl. Phys. Lett. 10 (2012) 211104.77] G. Hwang, W. Han, J. Park, S. Kang, Sens. Actuators B 135 (2008) 309–316.78] H. Mbarek, M. Saadoun, B. Bessais, Mater. Sci. Eng. C 26 (2006) 500–504.79] M. Fekete, R. Hocking, S. Chang, C. Italiano, A. Patti, F. Arena, L. Spiccia, Energy

Environ. Sci. 6 (2013) 2222–2232.80] B. Weng, R. Shepherd, K. Crowley, A. Killard, G. Wallace, Analyst 135 (2010)

2745–2789.81] I. Chronakis, S. Grapenson, A. Jakob, Polymer 47 (2006) 1597–1603.
82] S. Waghuley, S. Yenorkar, S. Yawale, S. Yawale, Sens. Actuators B 128 (2008)
366–373.83] B. Weng, A. Morrin, R. Shepherd, K. Crowley, A. Killard, P. Innis, G. Wallace, J.

Mater. Chem. 2 (2014) 793–799.84] J. Stejskal, M. Omastova, S. Fedorova, J. Prokes, M. Trchova, Polymer 44 (2003)

1353–1358.

ors B 243 (2017) 919–926

85] E. Gill, A. Arshak, K. Arshak, O. Korostynska, Sensors 7 (2007) 3329–3346.86] A. Kros, S. Hovell, N. Sommerdijk, R. Nolte, Adv. Mater. 13 (2001) 1555–1557.87] G. Istamboulie, T. Sikora, E. Jubete, E. Ochoteco, J. Marty, T. Noguer, Talanta 82

(2010) 957–961.88] S. Zuo, Y. Teng, H. Yuan, M. Lan, Anal. Lett. 41 (2008) 1158–1172.89] G. Cui, S. Kim, S. Choi, H. Nam, G. Cha, Anal. Chem. 72 (2000) 1925–1929.90] E. Crouchm, D. Cowell, S. Hoskins, R. Pittson, J. Hart, Anal. Biochem. 347

(2005) 17–23.91] S. Sanchez, M. Roldan, S. Perez, E. Fabregas, Anal. Chem. 80 (2008) 6508–6514.92] E. Moczko, G. Istamboulie, C. Calas-Blanchard, R. Rouillon, T. Noguer, J. Polym.

Sci. Pol. Chem. 50 (2012) 2286–2292.93] A. Crew, D. Lonsdale, N. Byrd, R. Pittson, J.P. Hart, Biosens. Bioelectron. 26

(2011) 2847–2851.94] R. Moakhar, G. Goh, A. Dolati, M. Ghorbani, Electrochem. Commun. 61 (2015)

110–113.95] N. Makarova, E. Kulapina, Sens. Actuators B 210 (2015) 817–824.96] K. Itaya, I. Uchida, V. Neff, Acc. Chem. Res. 19 (1986) 162–168.

Biographies

Wanqin Jin is Professor of chemical engineering at Nanjing Tech University andHis current research focuses on the development of membrane and biosensingmaterials, electrochemical analysis and the production transfer of biosensors byscreen-printing technique. He was an Alexander von Humboldt Research Fellow(2001), and a visiting Professor at Arizona State University (2007) and HiroshimaUniversity (2011, JSPS invitation fellowship). He has published over 250 interna-tionally refereed journal papers and edited a book on materials-oriented chemicalengineering. He serves as associate editor and an editorial board member for severaljournals and is a council member of the Aseanian Membrane Society.

Zhenyu Chu received his B.Sc. and Ph.D. degree in chemical engineering from theDepartment of Chemistry and Chemical Engineering, Nanjing Tech University, Chinain 2008 and 2013. He studied in Institute of Technology Tallaght, Dublin, Ireland for

Jingmeng Peng received her B.Sc. degree from the Department of Chemistry andChemical Engineering, Changchun University of Science and Technology, China in2012. She is now an assistant engineer at Nanjing Tech University.

Sensors and Actuators B: Chemical · most nanomaterial synthesis methods can hardly realize the large-scale preparation of nanomaterials on electrode due...

Documents