In Situ Synthesis of Gold Nanoparticles on Poly (L-arginine) Modified Glassy Carbon Electrode and Electrocatalytic Oxidation of Glucose in Alkaline Solution

Abstract

In situ synthesis of gold nanoparticles on poly (L-arginine) modified glassy carbon electrode using poly (L-arginine) as reduction agent is reported. EDAX pattern suggests that the gold nanoparticles can be in situ synthesized on poly (L-arginine) modified glassy carbon electrode. SEM image shows that the gold nanoparticles are well dispersed on the surface of glassy carbon electrode. The as-synthesized gold nanoparticles show excellent electrocatalytic activity for the oxidation of glucose. This strategy provides an in situ approach to prepare gold nanoparticles modified electrode using poly (amino acid) as reduction agent for sensor and catalytic applications.The synthesis of gold nanoparticles (AuNPs) has received considerable attention due to its optical, electronic and catalytic properties. 1,2 The modification of AuNPs on the electrode can bring high active electrode surface area and good conductivity, which enable a wide range of potential applications including fuel cells, 3 and electrochemical sensors such as non-enzymatic glucose sensors 4-6 and enzymatic glucose biosensors. 7-9 Now, there are a number of synthesis methods for obtaining AuNPs such as electrochemical, photoirradiation, ultrasonic irradiation and seed mediated growth processes. 10 These methods can be divided into two categories depending on whether the nanoparticles are grown in a non-polar organic medium or a polar medium such as water. 11 The synthesis of AuNPs in a non-polar medium is generally prepared via reduction of HAuCl 4 by NaBH 4 or citrate in the presence of a stabilizer containing at least one -NH 2 or -SH group. 12 On the other hand, water-soluble AuNPs have long been synthesized by reduction of HAuCl 4 using citrate in aqueous solution. 13 Recently, the water-dispersible AuNPs were synthesized by reduction of HAuCl 4 using amino acids in aqueous solution. Selvakannan et al. reported that the water-dispersible AuNPs prepared by the spontaneous reduction of aqueous chloroaurate ions using tryptophan. 14 Wangoo et al. demonstrated that synthesis of a stable gold hydrosol by using glutamic acid as reduction agent. 12 The other amino acids, such as L-arginine, L-lysine, L-aspartic acid and L-tyrosine, were also used as reduction agent to synthesis of water-dispersible AuNPs. 11,15 L-arginine is a well-known amino acid, which can be easily electropolymerized on electrode surface to form a poly (L-arginine) (PLA) film. 16,17 PLA polymer cannot only bear amino groups but also provide the matrix bridges. 18,19 In this study, we report an in situ synthesis of AuNPs on PLA modified glassy carbon electrode (GCE) using PLA as reduction agent. The AuNPs on the modified electrode were characterized by EDAX and SEM. The electrocatalytic activity of the synthesized AuNPs for glucose oxidation in alkaline solution was also evaluated. ExperimentalReagents.-All the reagents were bought from local commercial sources with analytical grade. 0.2 M Na 2 HPO 4 and 0.2 M NaH 2 PO 4 solutions were mixed to form a phosphate (PP) buffer solution (0.2 M...

Aminosilane-Assisted Electrodeposition of Gold Nanodendrites and Their Catalytic Properties

“…5(a), in the absence of glucose, the cathodic peaks of the reverse scan at 0.16 V and 0.14 V correspond to the reduction of gold oxide produced in the forward scan. In the presence of glucose, the anodic peaks in the forward scan at −0.46 V correspond to the peaks of partial oxidation of glucose, which causes electrosorption of glucose to form adsorbed intermediate, and the anodic peak at 0.24 V represents the direct oxidation of glucose to gluconolactone5152. The reverse scan shows a strong anodic peak at 0.16 V that is formed by the direct oxidation of glucose.…”

“…The reverse scan shows a strong anodic peak at 0.16 V that is formed by the direct oxidation of glucose. Because the AuOH on the gold crystal surface is the active site for electro-catalytic oxidation of glucose to take place, the population of AuOH sites is greatly enhanced in the forward scan515253; hence, direct oxidation of glucose occurs in the reverse scan. To determine the sensitivity of the dendritic Au as a glucose biosensor, the amperometric responses of the electrode were recorded with the successive addition of different concentrations of glucose at 0.3 V. By calculating the slope of the calibration of the amperometric response, the sensitivity of the dendritic electrode under certain concentration can be evaluated5455.…”

Electrochemical Biosensor Based on l-Arginine and rGO-AuNSs Deposited on the Electrode Combined with DNA Probes for Ultrasensitive Detection of the Gastric Cancer-Related PIK3CA Gene of ctDNA

“…The EIS signals of GCE+poly­( l -arginine)+Go-AuNS composite electrodes were smaller than those EIS responses of bare GCE, l -arg, and Go-AuNS composite, which suggests a positive effectiveness of the electrochemical charge transfer rate. This may be the cause of the presence of physisorption attraction between the basal plane of the GO-AuNS composite and the l -arginine monomers with rich aromatic ring groups. , As a result, the higher number of nucleation sites were created and greatly enhanced the electropolymerization efficiency. The EIS response of the GCE+ l -arginine+Go-AuNS composite electrodes (Figure D) showed a smaller R ct value compared with that of both the poly­( l -arginine) and Go-AuNS nanocomposite (Figure B, C), proving that addition of l -arginine significantly improved the electrochemical charge transfer efficiency of the Go-AuNS nanocomposite.…”

Electrochemical Detection of Melamine by Using Reduced Graphene Oxide–Copper Nanoflowers Modified Glassy Carbon Electrode

“…Many researchers used poly amino acid to modify electrodes due to their excellent electrocatalytic properties. , For instance, poly­( l -arginine) can be spontaneously electropolymerized on the surface of electrodes for its significant outlook through the coalescence of −NH 2 and −COOH. , It was reported that poly­( l -arginine) improves the electrode response stability and the analytes electroactivity …”

“…15,16 For instance, poly(L-arginine) can be spontaneously electro- polymerized on the surface of electrodes for its significant outlook through the coalescence of −NH 2 and −COOH. 17,18 It was reported that poly(L-arginine) improves the electrode response stability and the analytes electroactivity. 16 Inorganic nanoparticles incorporated with graphene oxide (GO) were reported to lead extraordinary function for electrode modification.…”