Italy, Salento, Lecce. NNL- National technology laboratories.

Italy, Salento, Lecce

NNL- National technology laboratories

Hybrid systems for biosensing on chip

V. Arima

National Nanotechnology Laboratory of INFM-CNR

HI-Tech. – District – ISUFIUniversity of Lecce

IIT- Italian Institute of TechnologyVia Arnesano 73100 LECCE – ITALY

[email protected]

Outline

Biosensing in nanotechnologyThe electrical approachOptical detection (Dr. P.P.Pompa)

Biosensing in nanotechnology

Fast and reliable detection of substances important to human welfare is much-needed, both in medicine and in the food industry. To this end, biosensors play an important role. The sensors will typically represent a combination of biochemistry, electronics or optics and surface chemistry

Electrochemical biosensors

Many leading devices for self-measurement of blood glucose are based on static electrochemistry. A fixed input signal (such as an applied voltage) from the blood glucose meter results in an output signal that correlates to the glucose concentration in the sample

AgaMatrix device

DNA chips

Amplification area using PCR

Detection area

inlet

sensor for temperature control

heater outletgold electrode

Connection to PCB

inlets for the liquids

continuos flow of liquids from the inlets to the detection area through microchannels

PCR cycles during the flow

K. Sun et al. / Sensors and Actuators B 84 (2002) 283–289

Chips for amplification and detection of DNA in organic fluids

Outline

Biosensing in nanotechnologyThe electrical approachOptical detection (Dr. P.P.Pompa)

Geometry of devicesPlanar-nanotips - EBL

Interdigited nanoelectrods

photolithography

Mesa structures - photolithography

Surface chemistry

Biomolecules interconnected to nanodevices: the azurin

example Azurin monolayers on silicon oxide Azurins on gold

Azurin mediates electron-transfer in the denitrifying chains of Pseudomonas aeruginosa

ET by means of a reversible redox reaction involving the copper site (two stable electronic configurations: Cu(I) and Cu(II))

The disulfide bridge allows chemisorption

Azurin monolayers on silicon oxide

NC-AFM images of WT Azurin immobilized on SiO2 functionalized by a self-assembled 3-MPTS monolayer employing the disulfide bridge

G.Maruccio et al , Adv. Mat., 17, 816-822 (2005)

RMS increases from 0.3 to 3.17nm; lateral dimension (after tip deconvolution) around

4nm in agreement with crystallographic data

Azurins on gold

V. Frascerra et al, IEEE Transactions on Nanotechnology (T-NT) 4, 637-640 (2005)

(a) Azurin immobilized on Au(111) for STM experiments (b) Three dimensional STM view showing azurin molecules adsorbed on Au (111) recorded in air. Bias voltage, -700mV, current setpoint, 1nA. Scan area, 130x130 nm2; vertical range, 0.6 nm. Scan rate 4Hz. (c) STM topographic image of azurin adsorbed on Au(111) acquired in constant-current mode in air. The proteins are clearly visible as bright spots. (d) Height profile of azurin imaged by STM. The lateral size (FWHM) around 4-6 nm is in good agreement with the reported crystallographic data.

50nM sodium acetate, pH 4.6

(isoelectric point) at 4°C for 1.5h

Planar-nanotips Typical open-circuit

resistance greater than 1 TΩ (100fA at 6V)

High throughput (90%)

Transport experiments at the surface of a solid

G. Maruccio et al., Microelectronic Engineering 67-68, 838-844 (2003)

Pre-exposure technique

Planar devices

Left scale: I(V) characteristics of devices made with azurin variants for two different gate voltages.

Right scale: Simulated current-voltage characteristics (red curve) of the protein FET for a device containing 8 protein chains connecting the source and the drain (Vg=1V was assumed in the calculation)

G.Maruccio et al , Adv. Mat., 17, 816-822 (2005)

Intermolecular transport by hopping

Au-cyanide electroplating

set-up

Bath temperature 55 oC, pH=4.3 Reference electrode: 20 cm2

Anode-Cathode Current: 70 mAAnode-Cathode distance: 7 cm

Towards single-molecule devices

0 5 10 15 20 25 30

0

20

40

60

80

100

Sep

arat

ion

(nm

)

Process Duration (sec)

Lateral Growthrate 1.66 nm/sec

Lateral Growthrate 2. 5 nm/sec

0 5 10 15 20 25 30

0

20

40

60

80

100

Sep

arat

ion

(nm

)

Process Duration (sec)

Lateral Growthrate 1.66 nm/sec

Lateral Growthrate 2. 5 nm/sec

0 5 10 15 20 25 30

0

20

40

60

80

100

Sep

arat

ion

(nm

)

Process Duration (sec)

Lateral Growthrate 1.66 nm/sec

Lateral Growthrate 2. 5 nm/sec

P. Visconti et al., Mater. Sci. Eng. C-Biomimetic Supramol. Syst. 23 (6-8), 889-892 (2003).P. Visconti et al., Nanotechnology 15 (7), 807-811 (2004).

Low throughput (20-30%)

Reduction of leakage current

G.Maruccio et al. , Small (in press)

Al-rich layers converted into a stable native oxide in a home-made oven after the cap layer removal

continuous flow of water steam carried by N2 gas

2 2 3 2 3 22 6 6AlAs H O Al O As O H

All processes at wafer scale Low-cost mass production of nanoscale circuits

Mesa nanostructuresDominant features: maxima in the range ±2.2 V ÷ ±3.4 VNDR due to resonant tunneling resulting from the alignment of two narrow energy states localized on Cu(II) and in the region of RSSR bridge Molecular features gradually disappear after a couples of weeks

G.Maruccio et al , Small (in press)

Interdigited electrods: towards an azurin-based

biosensor

Voltammograms of native azurin and its derivatives onto interdigited Cr/Au electrodes (the reference electrode was Au tip coated with silver or saturated calomel)

gel

Solution

Electrical detection in DNA chips

C.-Y. Tsai et al. Microsystem Technologies 11 (2005) 91–96

PCR chipsPCR (Polymerase Chain Reaction) is a chemical amplification

reaction of DNA. PCR is a highly specific reaction, capable of

creating large amounts of copied DNA fragments from minute

amounts of samples

Micro-chamber for PCR in PDMS

Nano-heaters electrodes

AcknowledgementsGiuseppe MaruccioAntonio Della TorreAlessandro BramantiElisabetta PrimiceriEliana D’AmoneDiego MangiulloStefania SabellaVanessa FrascerraAdriana BiascoPaolo ViscontiPasquale MarzoRoman KrahneRoss RinaldiFranco CalabiRoberto Cingolani

The authors gratefully acknowledge the support by the SAMBA (Self-Assembling of copper Metalloproteins at nanoscale for Biodevice Applications) European project, the IIT and the Italian MIUR (FIRB Molecular Nanodevices)