Synthesis of electroactive mesoporous gold–organosilica nanocomposite materials via a sol–gel process with non-surfactant templates and the electroanalysis of ascorbic acid

Abstract

Electroactive mesoporous organosilica nanocomposites (EMONs) and electroactive mesoporous goldorganosilica nanocomposites (EMGONs) were successfully prepared in this work and were applied in ascorbic acid (AA) sensing. EMONs were synthesized by using an aniline pentamer (AP) as an electroactive segment which controlled the redox ability and influenced the degree of sensitivity of the nanocomposites towards AA. EMGONs were successfully prepared by a one-pot synthesis in HAuCl 4 aqueous solution with different concentrations. Gold nanoparticles (AuNPs) were selectively reduced on an AP segment in an EMON matrix, which acted as a reductant as well as providing a large surface area to absorb and react with chloroaurate anions (AuCl 4 À ). The gold particle size can be controlled by varying the concentration of HAuCl 4 (aq.), and distributed AuNPs with controllable size were fabricated for the EMGONs. A sensor constructed from an EMGON-modified carbon-paste electrode (CPE) demonstrated 21-fold and 6.3-fold higher electrocatalytic activity towards the oxidation of AA compared to those constructed using a bare CPE and EMON-modified CPE, respectively. The high surface area of the EMGON-modified CPE exhibited a good electrochemical response towards AA at a low oxidative potential with good stability and sensitivity and a wide linear analytical detection range.

Mesoporous Materials‐Based Electrochemical Sensors

“…In this respect, mesoporous silica is probably the material offering the widest range of surface modification and functionalization, as illustrated in Figure 5 for the various systems used to date in electrochemical sensors. The simplest strategy (see top of Figure 5) is the adsorption of organic molecules likely to act as ligand (acetylacetonate, acac 164) or receptor (β‐cyclodextrin, β‐CD 165) for selective recognition of target analytes, or the immobilization of nanoparticles (such as gold 166, titanium 167, Ni(OH) 2 168, or bimetallic Ag/Mo 169) acting as catalysts, or the deposition of redox‐active polymeric materials (poly(vitamin B1) 170, poly(4‐vinylpyridine)‐[Os(bpy) 2 Cl] + 171). The interactions expected to be involved in this process are weak, making questionable the long‐term stability of the resulting hybrid materials.…”

Design of Double-Shelled CuS Nanocages to Optimize Electrocatalytic Dynamic for Sensitive Detection of Ascorbic Acid

“…(3) the two thin shells of 2-CuS NCs accelerated the transfer rate of catalytic electron, which was confirmed by above EIS analysis. Compared with the previously reported literatures, 2-CuS NCs/GCE exhibited higher electrochemical performance in terms of high sensitivity and low LOD as shown in Table 1 [ [29][30][31][32][33][34][35], demonstrating that 2-CuS NCs was ideal for analytical sensing of AA.…”

Photoisomerization of electroactive polyimide/multiwalled carbon nanotube composites on the effect of electrochemical sensing for ascorbic acid

“…. The differential pulse voltammetry (DPV) data of 20 µmol L −1 AA, 60 µmol L −1 DA and 120 µmol L −1 UA mixtures in PBS (pH 7.0) show well‐resolved anodic peaks at −0.03, 0.13 and 0.38 V, respectively . The oxidation of DA and UA does not influence the current response of AA.…”