Sunlight-Induced RAFT Synthesis of Multifaceted Glycopolymers with

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Sunlight-induced RAFT Synthesis of Multifaceted Glycopolymers with Surface-anchoring, In-situ AgNP Formation and Antibacterial Properties Lun Peng, Yan Luo, Yuqing Zheng, Weidong Zhang, and Gaojian Chen ACS Appl. Nano Mater., Just Accepted Manuscript • DOI: 10.1021/acsanm.8b00286 • Publication Date (Web): 30 Apr 2018 Downloaded from http://pubs.acs.org on May 6, 2018

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ACS Applied Nano Materials

Sunlight-induced RAFT Synthesis of Multifaceted Glycopolymers with Surface-anchoring, In-situ AgNP Formation and Antibacterial Properties Lun Peng,§† Yan Luo,§‡ Yuqing Zheng,† Weidong Zhang*† and Gaojian Chen*†,‡ †

Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, P. R. China.

‡

State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, P. R. China.

ABSTRACT A multifaceted glycopolymer is designed for convenient and universal fabrication of antibacterial surfaces. The sunlight-induced living radical polymerization in the presence of RAFT agent without photoinitiator was applied to obtain well-designed multifunctional glycopolymers containing three functional groups that can complex with silver ion, bind to different surfaces and form silver nanoparticles in-situ. The polymerization behavior and the effects of the concentration of the three monomers have been investigated. The obtained polymers can be used to effectively modify a variety of surfaces (silicon wafer, PDMS and stainless steel) and the modification is characterized by CA, FTIR, XPS, AFM and SEM. In addition, the effect of composition of polymers on the antibacterial property of different surfaces have been studied.

KEYWORDS: surface modification, dopamine, glycopolymer, silver nanoparticles, 1

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antibacterial

INTRODUCTION Silver (Ag) as a noble metal has been used to control spoilage and prevent infections for centuries.1 Especially, it is found that silver has germicidal effects in killing lower organisms while it has very low toxicity toward higher animals’ cell.2-4 Silver and especially in the form of nanoparticles, the old while promising antimicrobial agent, received the attentions again for preventing microorganisms at very low concentrations.5-8 It is reported that smaller size of silver nanoparticles is found to have better antimicrobial activity.8-12 We aim to fabricate surfaces with thin antimicrobial polymeric layers that possess silver nanoparticles with enhanced stability and performance. Sangermano and Yagci reported that polymer/silver nanocomposites can be prepared in-situ via simultaneous photoinduced polymerization and electron transfer, various functional silver-containing nanomaterials can be obtained in one-pot.13-15 It is widely known that silver nanoparticles can be prepared via Tollens process, where both aldehydes and reducing sugars can be employed.16 Here we designed and synthesized a novel glycopolymer with antimicrobial properties that could easily bind to any surfaces and form silver nanoparticles in situ in the fabrication process without using any reducing agents such as NaBH4, citrate, and ascorbate. The polymer contains three key units: silver ion loading unit, surface binding unit and silver ion reduction unit. More specifically, the carboxylic groups are introduced for conjugating silver ions,8, 17-20 the catechol groups are used as the anchor to immobilize onto different surfaces,21-26 and the sugar groups are used

2


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for reducing silver ions16,27, 28 and enhancing the bacteria killing ability due to the widely available carbohydrate receptors exist on the surface of bacteria.29 It should be noted that the dopamine units also possess metal reduction ability which can help in the formation of Ag nanoparticles.30 The key is to successfully synthesize well-defined polymers with the above mentioned three functional units. It is well known that acid groups will poison metal-catalysed living polymerization system; and dopamine will be easily oxidized and self-polymerize under alkaline conditions at high temperature. Glycopolymers31-34 can be prepared in different strategies especially via reversible addition fragmentation chain transfer living radical polymerization (RAFT)34-38 and copper catalysed living radical polymerization39-43. In addition, copolymers containing sugar moieties and methacrylic acid (MAA) were obtained conveniently via RAFT polymerization.44 Protected monomer strategy has been used to synthesize catechol-containing polymer.45 And using dopamine-bearing initiator/iniferter or monomer, dopamine-containing polymers were prepared successfully via methods such as single electron transfer living radical polymerization (SET-LRP) and photoiniferter-mediated polymerization where the polymerization normally proceeds at room temperature.22, 23, 25, 46,47 In our previous reports, sugar moieties and catechol groups were successfully integrated into one polymer via single electron transfer and reversible addition fragmentation chain transfer living radical polymerization (SET-RAFT), which could be immobilized onto many surfaces,48 and to guide cell growth.49 However SET-RAFT is not a good choice for preparing the designed polymer in this project as the catalyst copper can complex with carboxylic groups. Photo-induced RAFT polymerization50-52 can be carried out at ambient temperature 3



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and also avoid the possible problem caused by metal catalyst. It is reported by Qiao and Boyer that some trithiocarbonate and xanthate compounds can be photolyzed and drive the RAFT polymerization under visible light.52-54 And in our previous work, we have demonstrated that dithioesters such as 2-cyanoprop-2-ylα-dithionaphthalate (CPDN) and 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid (CPADB) can be photoactivated under sunlight to in situ produce free radical and initiate RAFT polymerization.55 Herein the sunlight-induced RAFT polymerization without photoinitiator reported in our recent work,55, 56

was taken to prepare the novel glycopolymer containing the sugar, carboxyl and catechol

groups. The polymerization behaviours, the immobilizing ability onto different surfaces and the antibacterial property of modified surfaces have been investigated in detail. EXPERIMENTAL SECTION Materials. Methacrylic acid (MAA; Macklin) was passed through a column of activated neutral alumina before use. 4-Cyano-4-(phenylcarbonothioylthio)pentanoic acid (CPADB) was purchased from Sigma-Aldrich and polydimethylsiloxane (PDMS) was purchased from Dow Corning, USA. Dimethyl sulfoxide (DMSO), silver nitrate (AgNO3), potassium carbonate (K2CO3), sodium hydroxide (NaOH) and methacryloyl chloride (stabilized with mehq, 97%) were purchased from Sinopharm Chemical Reagent Co., Ltd. D(+)-Glucosamine hydrochloride (TCI) was used as received. N-3,4-dihydroxybenzenethyl methacrylamide (DMA),57 2-(methacrylamido) glucopyranose (MAG)58 are synthesized according to the previous reports. Gram-negative Escherichia coli (E. coli) provided by the China General Microbiological Culture Collection Centre (Beijing, China) was used as received. LIVE/DEAD BacLight Bacterial Viability Kits were from Invitrogen. 4


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Photo-induced living radical polymerization of copolymer. A typical procedure for the polymerization is as follows. The monomer DMA (D), MAA (M1) and MAG (M2), together with the RAFT agent were dissolved in the DMSO, were added into a dried ampule with a stirring bar. No photoinitiator was added. After complete dissolution, the reaction mixture was bubbled with argon gas for 20 mins to eliminate the oxygen, then the ampule was flame-sealed and placed under the irradiation of solar light simulator (light intensity ∼0.54 mW cm-2) at room temperature. Then the ampule was opened at the designed time, and the polymers were precipitated from DMSO into the bulk of isopropanol. The samples were obtained by filtration and dried to constant weight under vacuum. The monomer conversion was determined by gravimetry. The molecular weights Mn(GPC) and polydispersity index (PDI) of the polymer were subsequently analyzed via a gel permeation chromatography (GPC). The molecular weights (Mn(NMR)) were calculated by 1H nuclear magnetic resonance (NMR). The detailed ratios of different monomer and RAFT agent are listed in the Table S1. Surface modification. The 2 mg glycopolymer was dissolved in 1 mL Tris-HCl solution (pH = 8.5), and the solution became weakly acidic due to the existence of -COOH. Then the mixture pH was adjusted to approximately 8.2 by adding 2 mM sodium hydroxide (NaOH). The treated dry surfaces (silicon, PDMS, stainless steel) were immerged in the solution overnight at room temperature and washed with deionized water for 3 times to remove the physically adsorbed polymers. The elution solution was collected and measured by UV-Vis to obtain the concentration (amount) of the polymer in the elution solution, then the amount of polymer modified on the surfaces was calculated. The amount of polymers modified on surface is calculated using the equation: polymer(on surface) = polymer(used) – polymer(in elution). 5



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The modified surfaces, dried in a desiccator, were used for the following surface characterization and bacteria experiment. Bacteria experiment. The modified surfaces mentioned above were placed in the clean culture dish. A 0.5 mg/mL silver nitrate (AgNO3) aqueous solution was added dropwise onto the surfaces at room temperature until all areas were covered. After 4 hours, the surfaces were washed with deionized water for 3 times and then placed in the desiccator. The amount of Ag in the elution solution was measured by ICP-MS, and the Ag immobilized on the surfaces was calculated based on the equation: Ag(on surface) = Ag(used) - Ag(in elution). Bacteria were grown in lysogeny broth (LB, 10 g/L bacto-tryptone, 5 g/L yeast extract, and 5 g/L sodium chloride) medium by overnight incubation at 37 oC with shaking (180 rpm). After washing with PBS (pH ~ 7.4) twice, the bacteria suspension at approximately 1×107 cfu/mL was added to the different surfaces and incubated for 3 h at 37 oC after which the samples were treated with BacLight Kits for 15 min at 37 oC. The samples were imaged using a fluorescence microscope. Characterizations. 1H nuclear magnetic resonance (1H NMR) spectra were recorded on a Bruker spectrometer (300 MHz) using D2O and DMSO-d6 as deuterated solvents. GPC was performed in water at a flow rate 1 mL/min on a Waters 1515 GPC system using PL aquagel-OH MIXED-M ×2 columns with a series of PEGs as standard samples at 30 oC. The modified surfaces were characterized with static water contact angle (CA) on a SL200C optical contact angle meter (USA Kino Industry Co., Ltd) at room temperature. UV-Vis absorption spectra were recorded on a Shimadzu (Kyoto, Japan) UV-3600. The chemical features on the surface before and after modification were identified by X-ray photoelectron 6


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spectroscopy (XPS, ESCALAB 250Xi using Al Kα X-rays, Thermo Scientific, USA). The fourier transform infrared spectroscopy (FTIR) experiments were performed on a Thermo Scientifc Nicolet 6700 FTIR. The wavenumber range of FTIR spectra is from 4000 to 400 cm−1. Inductively coupled plasma mass spectrometry (ICP-MS）was recorded on iCAPTM Qc (Thermo Fisher Scientific, USA). The amount of polymer modified on the surfaces was measured by Ultraviolet-Visible (UV-Vis) absorption spectra recorded on a UV-3600 (Shimadzu, Kyoto, Japan). The atomic force microscope (AFM) experiments were performed using an Asylum Research MPF-3D scanning force microscope. The spring constant of cantilever in a tapping mode is ca. 3 N/m, and resonance frequency is 75 kHz. Scanning electron microscopy (SEM, Hitachi S-4700) operating at 20 Kv was utilized to characterize the morphology of the surfaces and the average size of nanoparticles was further calculated. The images of bacteria adherent on the surfaces were acquired by an inverted fluorescence microscope (BX51, Olympus). RESULTS AND DISSCUSION Glycopolymer synthesis A series of glycopolymers containing catechol groups, sugar moieties and carboxylic groups were synthesized in the presence of reversible addition fragmentation chain transfer (RAFT) agent under light irradiation at room temperature (Scheme 1 & Scheme 2).

7



Scheme

Synthesis

1.

of

glycopolymers

with

surface-anchoring,

in-situ

NH

NH

silver-nanoparticle-formation and antibacterial properties.

Scheme 2. Sunlight-induced RAFT synthesis of glycopolymers.

a

90 1

30000

70

Mn (GPC)(g/mol)

60 50 40 30 20

25000 20000

b

c

80 70

Mn (GPC) Mn (th)

Conversion (%)

PDI

2

80

Conversion (%)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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15000 10000

60

D: M1: M2 0.1: 1: 5 1: 1: 5 0.1: 0.1: 5

50 40 30 20 10

5000

10 0

5

10

15

20

25

Time (h)

30

35

40

0

45 0 0

10

20

30

40

50

60

Conversion (%)

70

80

90

0

5

10

15

20

25

30

35

40

45

Time (h)

Figure 1. (a) Conversion vs time of polymerization under light irradiation at 25 0C; (b) dependence of the molecular weights (by GPC and theoretical values) and PDI on monomer 8


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conversions. Polymerization conditions are as follows: [M/R]0 = 150:1, [D/M1/M2]0 = 0.1: 1: 5, solvent DMSO = 1 mL. (c) Dependence of the conversion on monomer conversions for polymerization with different ratios of monomer, [M/R]0 = 150: 1, [M]0 = 1.13 mol/mL, [D/M1/M2]0 = 0.1: 1: 5 or 1: 1: 5 or 0.1: 0.1: 5. The polymerization was carried out without the addition of a photoinitiator. Table S1 summarize the polymerization under sunlight irradiation at room temperature with different ratios of monomers and monomer to RAFT agent. The Mn and PDI were analyzed by GPC and 1H NMR, and polymers with different targeting composition and molecular weight can be obtained with a narrow PDI. As shown in Figure 1a, with the increase of polymerization time, the monomer conversions increase, and it should be noted that an induction period of about 4h is observed, which could be attributed to the time for establishing the equilibrium between in situ activated radicals and RAFT agents.55 Moreover, the linear relationship between Mn(GPC) and monomer conversion with a narrow molecular weight distribution (PDI≤ 1.4) can be seen in Figure 1b. The Mn (GPC) data obtained were higher than theoretical values, which may be caused by the following two reasons: one is the difference between synthesized polymers and standards used for calibration; the other is referring to RAFT agent which in the polymerization is acting as both the chain transfer agent (CTA) and the initiator.59 We further performed experiments to study the effects of different concentration of monomers on the polymerization process by changing the monomer ratios. As shown in Figure 1c, the polymerization for DMA/MAA/MAG [D/M1/M2]0 = 1: 1: 5 is slower than that for 0.1: 1: 5, indicating that DMA will slow down the polymerization rate which may be due to the inhibition of DMA. Compared to DMA, the other two monomers MAA and MAG have little 9



effect on the polymerization rate. These results suggest that the polymerization under sunlight irradiation at room temperature is well controlled, and can be used for the preparation of polymers with designed three key elements.

a

h

d

g

e

a HOOC

O NH

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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j f b

n

b

c

O

Mn= 18700 g/mol,

HN

r OH HO q s OH O p t

Mw/Mn= 1.2

OH

m HO

d,e,f, OH

p-t -OH m

h,g,j

n 12

10

8

6

4

Chemical shifts (ppm)

2

0 10

12

14

16

18

20

Elution time (min)

Figure 2. Typical (a) 1H NMR spectrum of glycopolymer using DMSO-d6 as solvent and (b) molecular weights (Mn) and polydispersity index (PDI) by GPC, Mn = 18700, PDI = 1.2. Surface modification Sugar moieties are considered to be our bioactive components, DMA is used for surface attachment and MAA is used for complexation with silver ion (Ag+) to obtain the antibacterial properties. The 1H NMR and GPC spectra of the typical glycopolymer (Mn = 18700, PDI = 1.2, [D/M1/M2]0 = 1: 1: 5) are shown in Figure 2. The 1H NMR spectrum of the polymer (Figure 2a) displayed characteristic resonances at ca. 12 ppm (–COOH group), 6.0-7.0 ppm (dopamine group) and 2.9-5.5 ppm (sugar moieties), respectively. In order to confirm the silver reduction ability of the obtained polymer, it was dissolved in Tris solution and added with AgNO3. As shown in Figure S1, a new peak appears at approximately 440 nm, indicating the copolymer can reduce Ag+ into Ag(0) efficiently. For surface modification, the dopamine groups are first oxidized under the alkaline condition to adhere the glycopolymer 10


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to the surfaces, and then AgNO3 solution is dropped onto the surfaces, the Ag+ are captured by MAA and are reduced to AgNPs by MAG and free DMA moieties. Take silicon as an example, as shown in Figure 3a, after modification, in the FTIR spectra, peaks at ∼3340, 1730 and 1640 cm−1 are associated with hydroxyl bond and carbonyl bond of the copolymer, respectively, indicating the successful modification of glycopolymer on the surface. In addition, the peak at ∼400 eV (N 1s peak) in the XPS spectra from the polymer modified silicon can be observed in Figure 3b associated with sugar and dopamine units. The amount of polymer modified on the surface is about 0.0078 mg/cm2, obtained via the UV-Vis method. In the second step, an aqueous silver nitrate solution was dropped on the glycopolymer-modified surfaces and kept for 4 hours followed by washing with deionized water. The content of Ag in the elution solution was measured by ICP-MS and the amount (~0.0276 mg/cm2) of Ag immobilized on the surfaces was calculated. The typical XPS measurement of the modified silicon was performed as shown in Figure S2. The emergence of the silver peak (Ag 3d) confirms the successful silver immobilization on the glycopolymer modified surface. SEM image (Figure 3c, c′) presents the morphology of silver nanoparticles (spherical particles with the size of about 26 nm) on the modified surface. Furthermore, the AFM images (Figure 3d, d′) give the messages of glycopolymer layer on the modified silicon: the thickness is around 2 nm (the profile section besides the 2D AFM image) and the silver nanoparticles appear on the surfaces after AgNO3 treatment in Figure 3d″. Besides silicon, other representative substrates such as polydimethylsiloxane (PDMS) and stainless steel (SS) were chosen for investigation. After polymer modification, the static water contact angle (CA) for silicon, PDMS and SS surfaces decreased obviously from 55o to 24o, 11



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105o to 66o and 82o to 54o respectively (Figure 4), which is due to the successful immobilization of hydrophilic glycopolymers on the substrates. Furthermore, FTIR data from these surfaces are shown in Figure S3. In contrast with the clean substrates, the emergence of peaks from the modified surfaces indicate the successful modification of glycopolymer on the surfaces. Silver can be further loaded on the three surfaces conveniently via dropping AgNO3 solution (Figure S4).

Figure 3. (a) FTIR, (b) XPS spectra of the silicon without and with glycopolymer ([D/M1/M2]0 = 1: 3: 5) modification (Si + M); The SEM images of (c) silicon without modification and (c′) glycopolymer modified silicon after AgNO3 treatment and the AFM images of (d) silicon, (d′) glycopolymer modified silicon and its profile section, (d″) 12


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glycopolymer modified silicon after AgNO3 treatment.

Figure 4. The water contact angle of different surfaces without modification and modified with the glycopolymer. Antibacterial experiment As the surfaces were armoured with well-dispersed silver nanoparticles, the modified surfaces are expected to be antibacterial. Polymer with different ratios of carboxylic acid groups were first tested. As shown in the SEM images (Figure S5), even an excess of AgNO3 was used, the number of AgNPs formed is lowest for the polymer without MAA units, and more AgNPs formed with the increase of MAA in the composition. Aggregates of AgNPs with slightly bigger size were observed in the case of polymers with higher MAA composition. The MAA has an obvious effect on surface coverage while little effect on AgNPs size. To be precise, the AgNPs coverage increases with the increases of MAA composition in the polymer. These surfaces and control surfaces without AgNO3 treatment were immerged in 75% alcohol and then in sterile water to ensure the absence of any bacteria before antibacterial tests. After washing with PBS (pH ~7.4) twice, the bacteria suspension at approximately 1×107 cfu/mL was added to the different surfaces and incubated for 3 h at 37 o

C after which the samples were treated with BacLight Kits for 15 min at 37 oC. The samples 13



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were imaged using a fluorescence microscope. Green represents live bacteria while red means dead ones. It can be seen in Figure 5, without AgNO3 treatment, most bacteria stay alive on surfaces modified with only glycopolymer (>95%, Figure 5a-d). Both AgNO3 treatment and the silver-loading effect brought from the right amount of acid groups turn out to be essential. Although the same amount of AgNO3 were used for treatment, the live bacteria (green) decreased (from 62% to 2%, Figure 5a′′-d′′) with the increase of carboxyl acid content in one polymer chain. For polymers with a ratio of DMA: MAA: MAG = 1:3:5, most bacteria are killed effectively (2%, Figure 5d′′), due to the relatively higher loading of Ag nanoparticles, as shown in Figure S5. The glycopolymer with a ratio of DMA: MAA: MAG = 1: 3: 5 was further used for different surface modification and antibacterial tests. As shown in the Figure 6 a-c, lots of live E. coli (green) are adherent to the surfaces just modified with glycopolymer without AgNO3 treatment. On the contrary, almost all are dead on the surfaces with silver nanoparticles shown in Figure 6 a′-c′. It indicates that although glycopolymer itself cannot kill bacteria, surfaces can be modified by the glycopolymer conveniently and the modified surfaces can further form silver nanoparticles in-situ that can kill the bacteria effectively.

14


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Figure 5. The fluorescence microscope images of bacteria experiments on silicon surfaces modified with different glycopolymers (a: [D/M1/M2]0 = 1: 0: 5; b: [D/M1/M2]0 = 1: 1: 5; c: [D/M1/M2]0 = 1: 2: 5; d: [D/M1/M2]0 = 1: 3: 5) and corresponding surfaces with AgNO3 treatment (a′-d′, respectively). The green and red indicating living and dead E. coli respectively. Scale bar represents 50 µm. The quantitative analysis of the fluorescence intensities of each image are shown in a′′-d′′, respectively. Fluorescence intensity ratio (g/s) is referring to the intensity of green fluorescence to the overall fluorescence of each image.

15



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Figure 6. The fluorescence microscope images of bacteria experiments on surfaces (a) silicon, (b) PDMS, and (c) stainless steel modified with glycopolymer ([D/M1/M2]0 = 1: 3 :5) and corresponding surfaces with AgNO3 treatment (a′-c′). The green and red indicating living and dead E. coli respectively. Scale bar represents 50 µm. The quantitative analysis of the fluorescence intensities of each image are shown in a′′-c′′, respectively. Fluorescence intensity ratio (g/s) is referring to the intensity of green fluorescence to the overall fluorescence of each image. CONCLUSIONS In conclusion, the sunlight-induced living radical polymerization in the presence of RAFT agent

without

photoinitiator

was

successfully

applied

to

obtain

well-controlled

multifunctional glycopolymers bearing the carboxylic acid, the catechol and the sugar groups. 16


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The catechol groups are found to slow down the polymerization. The obtained polymer can be used to effectively modify different types of surfaces. Both AgNO3 treatment and the silver-loading effect brought from the right amount of acid groups turn out to be essential. By dropping silver nitrate solution to the surface, silver nanoparticles of about 26 nm can form in situ without adding reducing agents, and the resulting modified surface presents excellent antibacterial properties using polymers with the right composition. This work provides a novel method to prepare multifaceted glycopolymers with surface-anchoring and in-situ silver-nanoparticle-formation properties, which we believe has much potential for building bioactive surfaces with wide applications. ASSOCIATED CONTENT

Supporting Information The Supporting Information is available free of charge on the ACS Publications website at DOI: XX Polymers obtained with various conditions; UV-Visible absorption spectra; XPS spectra; FTIR spectra; and SEM images. AUTHOR INFORMATION

Corresponding Authors *E-mail: [email protected] *E-mail: [email protected]; Phone: +86-51265884406 ORCID Weidong Zhang: 0000-0002-6837-3060 17



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Gaojian Chen: 0000-0002-5877-3159 Author Contributions §

L.P. and Y.L. contributed equally to this work.

Notes The authors declare no competing financial interest. ACKNOWLEDGMENT The authors thank the National Natural Science Foundation of China (21774084, 21674074， 21374069) and the Natural Science Foundation of Jiangsu Province (No. BK20161208, BK20171208) for financial support. REFERENCES (1) Silvestryrodriguez, N.; Sicairosruelas, E. E.; Gerba, C. P.; Bright, K. R. Silver as A Disinfectant. Rev. Environ. Contam. T. 2007, 191, 23-45. (2) Neal, A. L. What can Be Inferred from Bacterium-nanoparticle Interactions about the Potential Consequences of Environmental Exposure to Nanoparticles? Ecotoxicology 2008, 17, 362-371. (3) Chernousova, S.; Epple, M. Silver as Antibacterial Agent: Ion, Nanoparticle, and Metal. Angew. Chem. 2013, 52, 1636-1653. (4) Xie, J.; Lee, J. Y.; Wang, D. I. C.; Ting, Y. P. Silver Nanoplates: From Biological to Biomimetic Synthesis. ACS Nano 2007, 1, 429-439. (5) Guo, Q.; Zhao, Y.; Dai, X.; Zhang, T.; Yu, Y.; Zhang, X.; Li, C. Functional Silver Nanocomposites as Broad-Spectrum Antimicrobial and Biofilm-Disrupting Agents. ACS Appl. Mater. Interfaces 2017, 9, 16834-16847. 18


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Table of Contents

A sunlight-induced RAFT approach to prepare well-defined multifaceted glycopolymers that can bind to different surfaces, form silver nanoparticles in-situ and kill bacteria.

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Sunlight-Induced RAFT Synthesis of Multifaceted Glycopolymers with

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