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Electronic Supplementary Information Switchable Polymer Brush System for Antifouling and Controlled Detection Serkan Demirci,* abc Selin Kinali-Demirci ac and Shan Jiang* b a Department of Chemistry, Iowa State University, Ames, IA 50011, USA b Materials Science and Engineering, Iowa State University, Ames, IA 50011, USA c Department of Chemistry, Amasya University, Amasya 05100, Turkey *Corresponding authors: E-mails: [email protected] (S.D.), [email protected] (S.J.). Experimental Materials -Cyclodextrin (CD, Aldrich), 2-N-morpholinoethyl methacrylate (MEMA, 95%, Aldrich), styrene (99.9%, Aldrich), 1-adamantlyamine (Ada, 97%, Aldrich), 4-cyano-4- (phenylcarbonothioylthio)pentanoic acid (CPDB, >97%, Aldrich), 4,4'-azobis(4-cyanovaleric acid) (ACVA, ≥98.0%, Aldrich), 2-bromopropionyl bromide (97%, Aldrich), 2,2'-bipyridyl ( ≥99%, Sigma-Aldrich), sodium azide (NaN 3 , ≥99.5%, Sigma-Aldrich), copper(I) bromide (99.999%, Aldrich), copper(II) bromide (99.999%, Aldrich), copper(II) sulfate (≥99.0%, Sigma-Aldrich), sodium hydride (60% dispersion in mineral oil, Aldrich), N,N'- dicyclohexylcarbodiimide (DCC, 99%, Aldrich), N-(3-dimethylaminopropyl)-N'- ethylcarbodiimide (EDC, ≥97.0%, Aldrich), N-hydroxysuccinimide (NHS, 98%, Aldrich), (+)- sodium L-ascorbate (≥98%, Sigma), hydrogen peroxide (30 wt.% in water, Sigma-Aldrich), allylamine (98%, Aldrich), propargyl bromide (80 wt. % in toluene, Aldrich), sodium bicarbonate (≥99.7%, Sigma-Aldrich), sodium hydroxide (≥98%, Sigma-Aldrich), sodium sulfate (≥99.0%, Sigma-Aldrich), sodium chloride (≥99%, Sigma-Aldrich), di-tert-butyl dicarbonate (≥98%, Sigma-Aldrich), magnesium sulfate (≥99.5%, Sigma-Aldrich), trifluoroacetic acid (TFA, 99%, Sigma-Aldrich), ammonium hydroxide (28.0-30.0%, Sigma- Aldrich), p-toluenesulfonyl chloride (≥98%, Sigma-Aldrich), tetraethylene glycol (99%, Aldrich), N,N,N',N'',N''-pentamethyldiethylenetriamine (PMDETA, 99%, Aldrich), 1-methyl- 2-pyrrolidinone (99.5%, Sigma-Aldrich), fluorescein isothiocyanate isomer I (FITC, ≥97.5%, Sigma) and acetone (≥99.8%, Sigma-Aldrich) were used as received without further purification. Chloroform (≥99.5%, Sigma-Aldrich), acetonitrile (MeCN, 99.8%, Sigma- Aldrich), dichloromethane (DCM, ≥99.8%, Sigma-Aldrich), ethyl acetate (EtOAc, ≥99.7, Sigma-Aldrich), N,N-dimethylformamide (DMF, 99.8%, Sigma-Aldrich), diethyl ether (Et 2 O≥99.0%, Sigma-Aldrich) and tetrahydrofuran (THF, ≥99.9%, Sigma-Aldrich) were purified by distillation according to published protocol. Silicon (100) wafers (single side polished, N-type) were purchased from Aldrich. Deionized water 18.2 MΩ.cm) was obtained from a Milli-Q water purification system (Millipore, Bedford, MA, USA). Hepatitis C virus antigen (HCV, ab49015), anti-hepatitis C antibody (anti-HCV, ab58713) and FITC labeled anti- hepatitis C antibody (FITC-anti-HCV, ab123076) were purchased from Abcam. 1 Electronic Supplementary Material (ESI) for Chemical Communications. This journal is © The Royal Society of Chemistry 2017
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Page 1: Detection Sigma-Aldrich), Switchable Polymer Brush System ... · Electronic Supplementary Information Switchable Polymer Brush System for Antifouling and Controlled Detection Serkan

Electronic Supplementary Information

Switchable Polymer Brush System for Antifouling and Controlled Detection

Serkan Demirci,*abc Selin Kinali-Demirciac and Shan Jiang*b

aDepartment of Chemistry, Iowa State University, Ames, IA 50011, USAbMaterials Science and Engineering, Iowa State University, Ames, IA 50011, USA

cDepartment of Chemistry, Amasya University, Amasya 05100, Turkey*Corresponding authors: E-mails: [email protected] (S.D.), [email protected] (S.J.).

ExperimentalMaterials-Cyclodextrin (CD, Aldrich), 2-N-morpholinoethyl methacrylate (MEMA, 95%, Aldrich), styrene (99.9%, Aldrich), 1-adamantlyamine (Ada, 97%, Aldrich), 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid (CPDB, >97%, Aldrich), 4,4'-azobis(4-cyanovaleric acid) (ACVA, ≥98.0%, Aldrich), 2-bromopropionyl bromide (97%, Aldrich), 2,2'-bipyridyl ( ≥99%, Sigma-Aldrich), sodium azide (NaN3, ≥99.5%, Sigma-Aldrich), copper(I) bromide (99.999%, Aldrich), copper(II) bromide (99.999%, Aldrich), copper(II) sulfate (≥99.0%, Sigma-Aldrich), sodium hydride (60% dispersion in mineral oil, Aldrich), N,N'-dicyclohexylcarbodiimide (DCC, 99%, Aldrich), N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC, ≥97.0%, Aldrich), N-hydroxysuccinimide (NHS, 98%, Aldrich), (+)-sodium L-ascorbate (≥98%, Sigma), hydrogen peroxide (30 wt.% in water, Sigma-Aldrich), allylamine (98%, Aldrich), propargyl bromide (80 wt. % in toluene, Aldrich), sodium bicarbonate (≥99.7%, Sigma-Aldrich), sodium hydroxide (≥98%, Sigma-Aldrich), sodium sulfate (≥99.0%, Sigma-Aldrich), sodium chloride (≥99%, Sigma-Aldrich), di-tert-butyl dicarbonate (≥98%, Sigma-Aldrich), magnesium sulfate (≥99.5%, Sigma-Aldrich), trifluoroacetic acid (TFA, 99%, Sigma-Aldrich), ammonium hydroxide (28.0-30.0%, Sigma-Aldrich), p-toluenesulfonyl chloride (≥98%, Sigma-Aldrich), tetraethylene glycol (99%, Aldrich), N,N,N',N'',N''-pentamethyldiethylenetriamine (PMDETA, 99%, Aldrich), 1-methyl-2-pyrrolidinone (99.5%, Sigma-Aldrich), fluorescein isothiocyanate isomer I (FITC, ≥97.5%, Sigma) and acetone (≥99.8%, Sigma-Aldrich) were used as received without further purification. Chloroform (≥99.5%, Sigma-Aldrich), acetonitrile (MeCN, 99.8%, Sigma-Aldrich), dichloromethane (DCM, ≥99.8%, Sigma-Aldrich), ethyl acetate (EtOAc, ≥99.7, Sigma-Aldrich), N,N-dimethylformamide (DMF, 99.8%, Sigma-Aldrich), diethyl ether (Et2O≥99.0%, Sigma-Aldrich) and tetrahydrofuran (THF, ≥99.9%, Sigma-Aldrich) were purified by distillation according to published protocol. Silicon (100) wafers (single side polished, N-type) were purchased from Aldrich. Deionized water 18.2 MΩ.cm) was obtained from a Milli-Q water purification system (Millipore, Bedford, MA, USA). Hepatitis C virus antigen (HCV, ab49015), anti-hepatitis C antibody (anti-HCV, ab58713) and FITC labeled anti-hepatitis C antibody (FITC-anti-HCV, ab123076) were purchased from Abcam.

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Amine terminated silicon waferst-Butyloxycarbonyl (t-BOC) protected allylamine was prepared by standard method.1 The procedure is follows: Allylamine (2.5 mL, 42.3 mmol) and chloroform (75 mL) were charged into a 250 mL flask. A solution of 3.75 g NaHCO3 in 75 mL of water was added to the reaction solution. Next, sodium chloride (8.06 g, 0.14 mol) was added along with 9.24 g (42.3 mmol) of di-tert-butyl dicarbonate dissolved in a few milliliters of chloroform. This mixture was refluxed for 90 min and extracted twice with 62.5 mL of diethyl ether (Et2O). The organic extracts were combined and dried over anhydrous magnesium sulfate, filtered and evaporated to remove the solvent. The t-BOC protected product was purified by vacuum distillation. Yield: 78.3%. 1H-NMR (600 MHz, CDCl3, δ, ppm): 5.88-5.76 (m, 1H), 5.20-5.05 (m, 1H), 4.50-4.77 (s, 1H), 3.79-3.65 (d, 2H), 1.43 (s, 9H). FTIR (ATR-FTIR) υ (cm-1): ~3200 (br, v, -NH), 3072 (v, H2C=CH-), 1705 (s, C=O), 1668 (s, O=C-N). ESI-HRMS: Found: m/z 158.1178. Calc. for C8H15NO2: [M-H]+ 158.1176.

Preparation of amine terminated silicon wafer (Si-NH2) was described in our previous works. 2,3 The silicon wafers were initially cleaned in a “piranha” solution, which is a 3:1 mixture of concentrated H2SO4 and H2O2 (30%) heated to 90 °C for 30 min (CAUTION: “piranha” solution reacts violently with organic materials and must be handled with extreme care), followed by copious rinsing with deionized water. The cleaned silicon wafers were etched for 1 min in a 2% hydrofluoric acid solution, quickly rinsed in degassed deionized water and dried in a stream of nitrogen. t-BOC protected allylamine (20 μL) was introduced onto the freshly prepared Si-H wafers. The prepares sample was sandwiched between two quartz plates, and a uniform thin liquid film of t-BOC protected allylamine formed on the Si-H wafers. The silicon wafer was placed in a N2 purged steel reaction chamber covered with a quartz window and irradiated with a UV light (λ= 254 nm) for 2 h. After irradiation, the modified silicon wafers were ultra-sonically washed with 25% TFA in methylene chloride followed by a minute rinse in 10% NH4OH to remove the t-BOC protecting group and dried in a stream of nitrogen.

4-Cyano-4-(phenylcarbonothioylthio)pentanoic acid N-succinimidyl ester (CPDBE)CPDBE was prepared according to the previously published protocol.4 CPDB, 2.79 g, 10 mmol) and NHS (1.15g, 10 mmol) were dissolved in 20 mL of anhydrous DCM. DCC (2.06 g, 10 mmol) was added to the solution. Than the mixture was stirred at room temperature in the dark for 24 h. A white product was filtrated out, and the filtrate was concentrated. The concentrated liquid was purified through a gel column with EtOAc/hexane (1:3, v/v) as eluent. Yield: 67.9%. 1H NMR (600 MHz, CDCl3, δ, ppm): 7.91 (d, 2H), 7.52-7.46 (m, 3H), 2.89 (s, 4H), 2.40-2.23 (m, 4H), 1.70 (s, 3 H). FTIR (ATR-FTIR) υ (cm-1): 2234 (v, -CN), 1740 (s, O=C-O), 1710 (s, C=O), 1040 (s, C=S). ESI-HRMS: Found: m/z 377.0621. Calc. for C17H16N2O4S2: [M-H]+ 377.0624.

Preparation of RAFT agent and initiator immobilized silicon waferThe Si-NH2 silicon wafers were placed into the solution of CPDBE (4.70 g, 12.5 mmol) in 50 mL of freshly distilled DCM. The reaction mixture was left to react at ambient temperature for 60 h. The silicon wafers were recovered from the reaction mixture and repeatedly washed with DCM and acetone and dried under a stream of nitrogen. RAFT agent immobilized silicon

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wafers were first placed in a 250 mL glass reactor with 50 mL anhydrous THF. This solution was cooled 0 C, and 2-bromopropionyl bromide (5.0 mL, 47.7 mmol) was added. The mixture was stirred at ambient temperature for 3 h. The silicon wafers were washed with THF and acetone and dried under a stream of nitrogen.

Surface initiated polymerizationThe polystyrene (PS) brushes were synthesized via SET-LRP. The solution of 2,2-bipyridine (54.7 mg, 0.35 mmol) in DMF (5.0 mL) was added to a clean and dry Schlenk tube. CuBr (50.2 mg, 0.35 mmol) was added to this solution, which was stirred and enveloped with a nitrogen stream. The solution was stirred at 50 C for 24 h to allow for complete dissolution/disproportionation of CuBr in the mixture. The solution of styrene (2.0 mL, 17.5 mmol) and 2-bromopropionyl bromide (18.0 L, 0.175 mmol) in DMF (5.0 mL) was added to the polymerization solution. The mixture was degassed by freeze-pump-thaw cycles. Silicon wafers were placed inthe glass reactor under nitrogen protection, and was held normal to the base of the reactor. The polymerization solution was then transferred into a glass reactor. The solution was heated to 90 C for 24 h. After the reaction, silicon wafers were cleaned with DMF, EtOAc, and acetone in an ultrasonic bath, and dried under a stream of nitrogen.

PS chains contain silicon wafers were placed in a glass reactor and degassed under vacuum for 30 min. MEMA monomer (4.18 g, 21.0 mmol) was added to a dry Schlenk tube along with CPDB (27.9 mg, 0.1 mmol), ACVA (14.0 mg, 0.05 mmol) and 1-methyl-2-pyrrolidinone (10 mL). The mixture was degassed by three freeze-pump-thaw cycles. The solution was transferred to the glass reactor, and was heated to 70 C for polymerization. After quenching the reaction in an ice bath, the PMEMA/PS brushes were washed with acetone and dried under a stream of nitrogen.

Tetraethylene glycol modified CDThe azide-CD was prepared as reported in our previous work.5 CD (63 g, 35.2 mmol) was dispersed in 500 mL of water and by the addition of NaOH solution (5.6 g in 20 ml water), CDs were completely dissolved. After stirring 1 h, the p-toluenesulfonyl chloride solution (9.5 g in 30 ml acetonitrile) was dropped into CD solution slowly. The suspension was stirred vigorously for 6 h and kept in refrigerator overnight. The precipitate white powder was filtered and dried under vacuum (12 g TsO-CD). In the second step, the TsO-CD (6 g) powder was dissolved in DMF (50 mL) and NaN3 (2.75 g, 42.3 mmol) was added into solution. This system was stirred at 80 C for about 24 h under nitrogen atmosphere and then, it was cooled to room temperature. Finally, the solution was dropped into cold acetone (600 mL) and the white precipitate of the product was obtained after the filtration. Yield: 47.5%. 1H NMR (600 MHz, DMSO-d6, δ, ppm): 5.84-5.59 (b, 14H), 4.93-4.78 (b, 7H), 4.58-4.40 (b, 7H), 3.80-3.49 (b, 20H). FTIR (ATR-FTIR) υ (cm-1): 3500-3200 (b, O-H), 2020 (-N3), 1100 (s, O-C-O). ESI-HRMS: Found: m/z 1182.3629. Calc. for C42H69N3O34: [M-Na]+ 1182.3655.

Tetraethylene glycol modified CD was synthesized according to a previously published report, 6 with some modification. Under nitrogen atmosphere, tetraethylene glycol (2 g, 10.3 mmol)

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was dissolved in 25 mL THF and was added dropwise to a THF solution of NaH (1.24 g, 60% dispersion in mineral oil, 30.90 mmol) via cannula at 0 C. Propargyl bromide (2.46 g, 20.6 mmol) was subsequently added dropwise to a reaction mixture at room temperature. The mixture was stirred at room temperature for 8 h. Saturated NH4Cl (200 mL) was added to the reaction mixture. And the mixture was extracted with EtOAc (3x100 mL). The organic phase dried over anhydrous MgSO4 then evaporated. Yield: 68.3%. 1H NMR (600 MHz, CDCl3, δ ppm): 4.19 (t, 4H), 3.70-3.60 (m, 16H), 2.16 (dd, 2H). FTIR (ATR-FTIR) υ (cm-1): 2960 (v, aliphatic C-H), 2120 (v, -CC), 1100 (s, O-C-O). ESI-HRMS: Found: m/z 271.1540. Calc. for C14H22O5: [M-H]+ 271.1540.

Scheme S1. Synthesis of tetraethylene glycol modified CD

Tetraethylene glycol modified CD was synthesized via a click reaction. Alkyl tetraethylene glycol (6.9 g, 25.5 mmol), CD-N3 (10.0 g, 8.5 mmol), PMDETA (1.77 mL, 8.5 mmol) and dried DMF (150 mL) were added to a Schlenk tube equipped with a magnetic stirring bar. The reaction mixture was degassed by purging with nitrogen for 30 minutes. The fresh solutions of sodium L-ascorbate (0.12 mmol, 21 mg) in 1.5 mL water and copper (II) sulfate (0.052 mmol, 8.8 mg) in 1.5 mL water were prepared and both added into the solution. The reaction mixture was stirred for 24 h at 50 C under N2. Then, the mixture was dropped in acetone and the product was obtained after the filtration. Yield: 52.6%. 1H NMR (600 MHz, DMSO-d6, δ, ppm): 8.04 (s, 1H), 5.86-5.65 (b, 14H), 4.91-4.82 (b, 7H), 4.55-4.45 (b, 7H), 3.80-3.48 (b, 33H), 3.44-3.36 (b, 7H), 2.13 (s, 1H). FTIR (ATR-FTIR) υ (cm-1): 3500-3200 (b, O-H), 2960 (v, aliphatic C-H), 2122 (v, -CC), 1100 (s, O-C-O). ESI-HRMS: Found: m/z 1430.5293. Calc. for C56H91N3O39: [M-H]+ 1430.5302.

Preparation of CD-functionalized silicon wafers The PMEMA/PS functionalized silicone substrates were placed in a glass reactor. DMF (100 mL) and NaN3 (2.0 g, 0.031 mol) were added to the reactor and subsequently degassed by purging with nitrogen for 30 minutes. The reaction was allowed to proceed at 80 C for 18 h. The PMEMA/PS-N3 wafers were rinsed with DMF and acetone in an ultrasonic bath, and dried under a stream of nitrogen. Tetraethylene glycol modified CD (1.5 g) was dissolved in DMF (25 mL). The substrates were immersed into the CD solution and degassed by purging with nitrogen for 30 minutes. The fresh solutions of sodium L-ascorbate (0.12 mmol, 21 mg) in 1.5 mL water and copper (II) sulfate (0.052 mmol, 8.8 mg) in 1.5 mL water were prepared and both

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of them added into the solution. The reaction mixture was stirred for 18 h at 80 C under N2. After cooling, PMEMA/PS-CD substrates were washed with DMF and acetone and dried under a stream of nitrogen.

Scheme S2. The preparation of the RAFT-In modified silicon wafers (RAFT agent/initiator=3.44).

Synthesis of Fluorescein isothiocyanate isomer I labeled 1-adamantylamine (FITC-Ada)FITC-Ada was synthesized according to a previously published report.7 FITC (250.0 mg, 0.642 mmol) was dissolved in 6 mL of anhydrous DMF. To this solution 240 μL of triethylamine was added. Subsequently, Ada (97.1 mg, 0.642 mmol) was added into the reaction mixture and stirred and kept at room temperature for 12 h under a nitrogen atmosphere. The concentrated solution was extracted with DCM/water, and the organic layer was separated. After the solvent was removed under vacuum, the solid was purified by silica gel column chromatography (Et2O:EtOAc, 2:1, v/v) to give the light-orange powder. Yield: 70.1%. 1H NMR (600 MHz, DMSO-d6, δ, ppm) 8.31 (s, 1H), 7.74 (dd, 2H), 7.14 (d, 1H), 6.9 (s, 2H), 6.70-6.50 (m, 6H), 2.27 (s, 6H), 2.10 (s, 3H), 1.66 (s, 6H). FTIR (ATR-FTIR) υ (cm-1): 3250 (s, N-H), 3080 (v, aromatic C-H), 1710 (s, O=C). ESI-HRMS: Found: m/z 541.1801. Calc. for C31H28N2O5S: [M-H]+ 541.1792.

Scheme S3. Synthesis of FITC-Ada.

Host-guest interaction between target molecules and CD-functionalized wafersFITC-Ada molecule was used as a target molecule for the determination of optimum thickness and the stimuli-responsive ability of polymer chains. The silicon wafers, which prepared with different polymerization time, were immersed in an aqueous solution (25.0 µM) of FITC-Ada at room temperature and 40 C for 24 h in the dark. After rinsing five times with deionized water, the fluorescence images of silicon wafers were recorded via fluorescence microscope. Fluorescence intensities were calculated from fluorescence images via ImageJ software. The

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silicon wafers were immersed in an acetate buffer solution (pH=5.2), phosphate buffered saline (PBS, pH=7.4) and Tris-buffered saline (pH=8.8). Afterward, the silicon wafers were placed in an aqueous solution (25.0 µM) of FITC-Ada at room temperature and 40 C for 24 h in dark, and fluorescence images were captured.

Scheme S4. Determination of optimum thickness and the stimuli-responsive ability of PMEMA chains with a fixed PS, of 6,300 g/mol and various polymerization time of MEMA.�̅�𝑛,𝐺𝑃𝐶

The switchable property of the PMEMA/PS-CD wafers was tested by using model organic compounds. First, PMEMA/PS-CD (unprotected) and cationic PMEMA/PS-CD (protected) wafers were placed on the supporting layer of desiccator (25 cm diameter) which was containing 5 mL aniline (a model chemical pollutant). The desiccator was sealed off, leaving the silicon wafers exposed to aniline vapor for times that were varied between 1 and 28 days at 24 and 40 C. After this exposure, the silicon wafers were removed from desiccator. The adsorption capability of these samples was tested by using phenolphthalein. The silicon wafers were immersed in phenolphthalein solution (0.1 M) which was adjusted to pH 7.4 by addition of PBS buffer solution for 12 h. And, the depletion of phenolphthalein from solution was determined by UV-vis spectrophotometry at 562 nm.

The effect of target molecule concentration on the adsorption capacity of the PMEMA/PS-CD wafer was studied by varying FITC-Ada concentration between 3.125 and 100.0 M. Immobilization of FITC-Ada on the PMEMA/PS-CD wafer was achieved at 40 °C for 24 h. Adsorption was determined by fluorescence microscope. The effect of adsorption time was studied at different time intervals (0–48 h) at 40 C. The FITC-Ada initial concentration was fixed at 25 M.

In order to test the reusability of PMEMA/PS-CD and cationic PMEMA/PS-CD wafers for FITC-Ada adsorption, five cycles of adsorption/desorption were carried out. After each adsorption/desorption cycle, adsorbed FITC-Ada on wafers was determined by fluorescence microscope, and immobilized FITC-Ada was washed three times at 45 C in ultrasonic bath and re-operated in a fresh FITC-Ada solution.

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Sandwich immunoassay1 g of HCV antibody was diluted in 1 mL acetate buffer (pH=5.2), and the solution of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) and NHS in PBS was added. The mixture was kept at 4 C for 30 min. After filtration of EDC and NHS, the buffer exchanged from acetate buffer (pH 5.2) and re-suspended the active product in 1 mL of PBS (pH 7.4). Ada was added to the solution at 4 C for 2 h. Modified anti-HCV was then purified using a YM-10 nominal weight cutoff filter. CD-functionalized polymer brushes were immersed in Ada grafted anti-HCV solution at 40 C for 24 h. These prepared samples were also reacted with HCV at 36 C for 1 h, and HCVs were assayed using FITC labeled anti-HCV.

Scheme S5. Schematic presentation of host-guest interaction between target molecule and PMEMA/PS-CD, and regeneration of PMEMA/PS-CD surface.

CharacterizationProton nuclear magnetic resonance (1H-NMR) experiment was performed on a Bruker Avance III at 600 MHz. Compounds were measured at room temperature in CDCl3 or DMSO-d6. Fourier transform infrared (FTIR) spectra were recorded on a Nicolet 6700 instrument (Thermo). High-resolution mass spectrometry (HRMS) analysis was performed on an Agilent 6540 QTOF spectrometer. Visible absorption spectra were obtained using a Perkin Elmer Lama 35 UV-vis spectrophotometer. Absorption spectra of phenolphthalein solution were collected using methanol as the solvent. The chemical composition information of the prepared silicon wafers was obtained by X-ray photoelectron spectroscopy (XPS); the measurement was carried out on a Thermo Scientific K-Alpha spectrometer using a monochromatic Al K- X-ray source (h = 1486.6 eV). Charging neutralizing equipment was used to compensate sample charging, and the binding scale was referenced to the aliphatic component of C 1s spectra at 284.8 eV. The water contact angle measurements were conducted at room temperature using a goniometer (DSA 100, Krüss) equipped with a microliter syringe. Deionized water (5.0 L) was used as the wetting liquid. The morphology of the silicon wafers was recorded on an atomic force microscope (Park Systems XE70 SPM Controller LSF-100 HS). A triangular-shaped Si3N4 cantilever with integrated tips (Olympus) was used to acquire the images in the noncontact mode. The normal spring constant of the cantilever was 0.02 N/m. The force between the tip and the sample was 0.87 nN. The ellipsometric measurements were performed under ambient conditions using an ellipsometer

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(model DRE, EL X20C) equipped with a He-Ne laser (λ=632.8 nm) at a constant incident angle of 75°. The average dry thickness of polymer brushes on silicon substrate was determined by fitting the data with a three-layer model. 8 The number-average molecular weights ( and the polydispersity index (PDI) of the free polymers were estimated by a �̅�𝑛)

Waters gel permeation chromatography (GPC), which was equipped with differential refractive index and UV detector. As eluent, THF with a flow rate 1.0 mL/min at a temperature of 30 C was utilized. Toluene was added as an internal standard. The system was calibrated with narrow molecular weight distribution poly(methyl methacrylate) standards. The free polymers were filtered through 0.45 m polytetrafluoroethylene membrane filter before injection. 1H NMR spectroscopy was used to determine the absolute

of homopolymers by comparing the integrated signal intensities. For PS, peaks at 0.92 �̅�𝑛

and 7.56 (due to the methyl group protons from the initiator and aromatic p-proton from the RAFT agent fragment) were used. And for PMEMA, peaks at 7.24-6.92 and 3.85-3.65 (due to the aromatic and morpholino ring protons of the monomer residues) were used. Fluorescence microscopy images were recorded by using an Olympus BX51 and Leica fluorescent microscope with a 40X objective.

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Result and Discussion

Fig. S1. 1H NMR spectra of t-butyloxycarbonyl (in CDCl3).

Fig. S2. HRMS spectra of t-butyloxycarbonyl.

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Fig. S3. 1H NMR spectra of CPSE (in CDCl3).

Fig. S4. ESI-HRMS spectra of CPSE.

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Fig. S5. 1H NMR spectra of CD-N3 (in DMSO-d6).

Fig. S6. ESI-HRMS spectra of CD-N3.

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Fig. S7. 1H NMR spectra of alkyl tetraethylene glycol (in CDCl3).

Fig. S8. ESI-HRMS spectra of alkyl tetraethylene glycol.

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Fig. S9. 1H NMR spectra of tetraethylene glycol modified CD (in DMSO-d6).

Fig. S10. ESI-HRMS spectra of tetraethylene glycol modified CD.

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Fig. S11. 1H NMR spectra of FITC-Ada (in DMSO-d6).

Fig. S12. ESI-HRMS spectra of FITC-Ada.

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Inte

nsity

(a.u

.)

168 165 162 159Binding Energy (eV)

S2pRAFT

Inte

nsity

(a.u

.)76 72 68 64

Binding Energy (eV)

Br3dRAFT-In

408 404 400 396Binding Energy (eV)

Inte

nsity

(a.u

.)

N1sPMEMA/PS-N3

Inte

nsity

(a.u

.)

292 284 276Binding Energy (eV)

C1sPMEMA/PS-CD

a

b

Fig. S13. XPS survey scan of the prepared samples (a) XPS wide scan of related samples (b).

Wavenumbers (cm-1)

PMEMA/PS

PS

1720 1100

3080 2960

Fig. S14. FTIR spectra of PS and PMEMA/PS samples.

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Fig. S15. 1H NMR spectra of PS homopolymer, Mn = 6,150 g/mol (in CDCl3).

Fig. S16. 1H NMR spectra of PMEMA homopolymer, Mn = 31,600 g/mol (in CDCl3).

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a b

Fig. S17. Kinetic plots of vs polymerization time, and plots of and vs 𝑙𝑛([𝑀]0 [𝑀]) �̅�𝑛𝑀𝑤 𝑀𝑛

conversion for SET-LRP of styrene (a) and RAFT ([𝑀]0 [𝐼]0 [𝐶𝑢𝐵𝑟]0 [𝐿]0 = 100:1:2:2)polymerization of MEMA (b).([𝑀]0 [𝐶𝑇𝐴]0 [𝐼]0 = 420 2 1)

pKa = 5.3

Fig. S18. The water contact angle as a function of pH.

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Fig. S19. AFM images of Si-NH2 (a) and PMEMA/PS-CD (b).

Fig. S20. Fluorescence microscopy images of CD-functionalized PMEMA/PS with a fixed PS of 6,300 g/mol with various polymerization time of MEMA.�̅�𝑛,𝐺𝑃𝐶

Fig. S21. Fluorescence microscopy images of PMEMA/PS-CD under different pH and temperature conditions.

Fig. S22. Relationship between fluorescence intensity and FITC-Ada concentration. Adsorption time and temperature were, respectively, 24 h and 40 C (A). The adsorption kinetics of the CD-functionalized PMEMA/PS surfaces. The concentration of FITC-Ada and temperature were 25 M and 40 C, respectively (B).

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Fig. S23 The reusability of the CD-functionalized PMEMA/PS surfaces. 1 – surface before immersion in FITC-Ada; 2 – surface after immersion; 3 – surface after sonication rinse at 45 C; 4 – surface re-immersed in FITC-Ada; 5-10 – surfaces repeated with sonication rinse and immersion procedure.

Table S1. Summary of the various characteristics of the prepared surfaces.

RAFT RAFT-In PS PMEMA/PS PMEMA/PS-N3

PMEMA/PS-CD

Thicknessa (nm) 3.20.7 3.40.9 5.10.9 35.40.2 - -

Static Contact Angle () 63 1 65 2 82 5 38 3 37 2 34 1

O/N/C/S/Br/Si b

26.6/2.9/53.2/5.6/ - /11.7

24.2/2.6/55.8/6.2/0.9/10.3

26.2/1.9/59.2/2.6/1.1/9.0

21.4/7.4/68.5/2.3/0.4/ -

22.9/9.3/65.7/2.1/ - / -

31.7/3.6/63.9/0.8/ - / -

(g/mol)�̅�𝑛,𝐺𝑃𝐶 - - 6,300 30,900c - -

(g/mol)�̅�𝑛, 𝑁𝑀𝑅 - - 6,150 31,600c - -

PDI - - 1.24 1.11c - -

aElipsometric thicknessbAtomic contentration of surfacesc and PDI for PMEMA�̅�𝑛

Table S2. Fitting parameters of the N1s and C1s XPS spectra of PS, PMEMA/PS, PMEMA/PS-N3 and PMEMA/PS-CD samples.

N1s C1sSamples

𝑁 = 𝑁 + = 𝑁 𝐶 ‒ 𝑁 𝑂 = 𝐶 ‒ 𝑂 𝑂 ‒ 𝐶 ‒ 𝑂 𝐶 ‒ 𝑂 𝐶 ‒ (𝐶 ‒ 𝐻)PS - 399.8 288.31 - 284.8Area ratio (%) 0 100 18.6 81.4PMEMA/PS - 400.1 289.3 - 286.4 284.8Area ratio (%) 0 100 13.2 38.0 48.8PMEMA/PS-N3 404.1 400.9 289.4 - 286.3 284.8Area ratio (%) 20.4 79.6 13.7 37.7 48.6PMEMA/PS-CD - 400.1 289.3 288.0 286.4 284.8Area ratio (%) 0 100 8.9 1.4 49.9 39.8

All spectra were energy calibrated with measured C1s peak position at 284.8 eV.1 𝑂 = 𝐶 ‒ 𝑁

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Nor

mal

ized

Flu

ores

cenc

eIn

tens

ity

1 2 3 4 5 6 7 8 9 100.0

0.2

0.4

0.6

0.8

Cycles (time of usage)

pH < pKa, pH > pKa

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