Electrochemical Detection of Hydrogen Peroxide by Inhibiting the p-Benzenediboronic Acid-Triggered Assembly of Citrate-Capped Au/Ag Nanoparticles on Electrode Surface

Abstract

Metal nanoparticles (NPs) possess unique physicochemical attributes for creating effective recognition and transduction processes in chem/bio-sensing. In this work, we suggested that citrate-capped Au/Ag NPs could be used as the reporters for the design of hydrogen peroxide (H2O2) sensors with a simple manipulation principle and an easy detection procedure. Specifically, p-benzenediboronic acid (BDBA) induced the aggregation of citrate-capped Au NPs through the cross-linking reaction between citrate and boronic acid of BDBA in solution. By modifying the electrode with a boronic acid derivative, the BDBA-induced assembly of Au NPs was achieved on the electrode surface. This led to a significant decrease in the electron transfer resistance due to the unique conductive ability of Au NPs. However, when the boronate group on the electrode surface was oxidized into its phenol format, the assembly of Au NPs on the electrode surface was not achieved. As a result, a higher electron transfer resistance was observed. The process could be monitored by electrochemical impedance technique. Furthermore, when Ag NPs were used instead of Au NPs in this design, the H2O2 concentration could be determined by measuring the linear-sweep voltammetry (LSV) current through the solid-state Ag/AgCl reaction of Ag NPs. The results indicated that NP-based colorimetric assays could be developed into more sensitive electrochemical analysis.

A sensitive and selective electrochemical biosensor for the determination of beta-amyloid oligomer by inhibiting the peptide-triggered in situ assembly of silver nanoparticles

“…[47][48][49][50][51][52][53][54][55][56][57][58][59] In particular, silver nanoparticles (AgNPs) offer clear advantages for the design of electrochemical (bio) sensors, such as a simple preparation procedure, a size-dependent optical property, facile surface modification, a high surface area and a low oxidation potential. [55][56][57][58][59] Based on the specific Aβ oligomer/PrP 95-110 interaction and the well-defined and signal-amplified electrochemical signal of AgNP aggregates, Xia et al 59 have developed an electrochemical biosensor for the determination of Aβ oligomer by using adamantine …”

Aggregation of Gold Nanoparticles Caused in Two Different Ways Involved in 4-Mercaptophenylboronic Acidand Hydrogen Peroxide

“…Additionally, the aggregation of 4-MPBA/AuNPs enhanced with the decrease of pH is also attributed to phosphate protonation, resulting in decrease of the charged number of the phosphate anion. In fact, not surprisingly, the aggregation of 4-MPBA/AuNPs often appears in the solution containing a salt buffer [10,12,25,26,27], and the stabilized 4-MPBA/AuNP solution is usually found in the case of KOH-adjusted pH values [8] or zwitterionic buffers with lower ionic strength (e.g., Tricine and Hepes) [28,29]. Thus, AuNP-based sensing strategies should pay special attention to the dispersion states of AuNPs affected by salt, DNA, proteins, or other ions [23].…”

Soft Template‐Directed Reactions: One‐Pot Synthetic Route for Bimetallic Core–Satellite–Shell Structured Electrocatalytic Nanospheres

“…Herein, the Tafel slope of Au@SiO 2 ‐Pt was 52 mV dec −1 , suggesting that the mechanism is a fast discharge reaction followed by either a rate‐limiting Heyrovsky reaction or Tafel reaction. The unique conductive ability of the Au core may result in a significant change in the charge transfer resistance, which facilitates the transport of electrons in solution. To further understand the ability of metal‐bound electrons, zeta potentials of Au@SiO 2 , Pt@SiO 2 , and Au@SiO 2 ‐Pt nanospheres were monitored in H 2 SO 4 (0.5 m) , and the zeta potential for commercial Pt/C was −32.4 mV (Figure S3 in the Supporting Information).…”