Sol-Gel Synthesis of Carbon Xerogel-ZnO Composite for Detection of Catechol.

Dawei Li,Qufu Wei,Quanfeng Dong,Kelong Ao,Jun Zang,Jin Zhang,Qingqing Wang

doi:10.3390/ma9040282

Abstract

Carbon xerogel-zinc oxide (CXZnO) composites were synthesized by a simple method of sol-gel condensation polymerization of formaldehyde and resorcinol solution containing zinc salt followed by drying and thermal treatment. ZnO nanoparticles were observed to be evenly dispersed on the surfaces of the carbon xerogel microspheres. The as-prepared CXZnO composites were mixed with laccase (Lac) and Nafion to obtain a mixture solution, which was further modified on an electrode surface to construct a novel biosensing platform. Finally, the prepared electrochemical biosensor was employed to detect the environmental pollutant, catechol. The analysis result was satisfactory, the sensor showed excellent electrocatalysis towards catechol with high sensitivity (31.2 µA·mM−1), a low detection limit (2.17 µM), and a wide linear range (6.91–453 µM). Moreover, the biosensor also displayed favorable repeatability, reproducibility, selectivity, and stability besides being successfully used in the trace detection of catechol existing in lake water environments.

Highlights

A biosensor, as a type of analytical tool, can be employed to detect analyte existing in various environments
Laccase (Lac) is a multicopper oxidase which can catalyze phenolic compounds to give their oxidation form accompanied by reduction of molecular oxygen [7]
Zinc acetate dihydrate (C4 H6 O4 Zn 2H2 O), formaldehyde, resorcinol, and other chemicals were purchased from the Sinopharm Group Chemical Reagent Co., Ltd. (Shanghai, China)

Summary

Introduction

A biosensor, as a type of analytical tool, can be employed to detect analyte existing in various environments. It consists of a biological recognition component and a physicochemical transduction device [1]. Clark invented enzyme based electrodes in 1962, enzyme based biosensors have attracted a great deal of attention from scientists and researchers [2,3,4]. Due to the great advantages of enzyme biosensors over conventional analytical techniques, such as low price, high sensitive/selective, rapid response, and amenable miniaturization, etc., they have been applied in multifarious fields, such as clinical medicine, environment monitoring, and food safety, as well as homeland security [5,6]. Laccase (Lac) is a multicopper oxidase which can catalyze phenolic compounds to give their oxidation form accompanied by reduction of molecular oxygen [7]

Methods

Results

Conclusion