The Facile Synthesis of Novel ZnO Nanostructure for Galactose Biosensor Application

Tran Viet Cuong,Quang Trung Tran,Ko Kang Bok,Phuong Ha La Phan,Duc Anh Dinh,Chang-Hee Hong

doi:10.1155/2019/2364327

Abstract

We introduce a novel structure of ZnO nanorods (NRs) grown on ZnO NRs (ZnO NRs/NRs) via a facile, low-cost, and environmentally friendly synthesis for galactose biosensor application. The galactose oxidase enzyme (GalOx) is immobilized on the ZnO NR/NR surface to form the novel electrode structure (GalOx|ZnO NRs/NRs). The GalOx|ZnO NR/NR electrode has a linear detection range of current density from 11.30 μA/mm2 to 18.16 μA/mm2 over a galactose concentration range from 40 mM to 230 mM, indicating the increment of electrode sensitivity up to 60.7%. The ZnO NR/NR morphology with a high surface area to volume ratio has a great contribution to the electrochemical performance of galactose biosensor. Our results propose a straightforward approach to fabricate architecturally ZnO-based nanostructure for biosensor application.

Highlights

Galactose (Gal), a common monosaccharide, is an important energy resource in living organisms [1]
The one-dimensional (1D) structure of ZnO NRs supplies good orientation and a large surface area which is favorable for enzyme immobilization
The SEM image of the ZnO NRs/NRs describes a novel morphology of the small ZnO NRs grown on the large ZnO NRs

Summary

Introduction

Galactose (Gal), a common monosaccharide, is an important energy resource in living organisms [1]. Many efforts have been focused on the development of metallic nanoparticle(NP-) based Gal biosensor, e.g., gold NPs, due to their good conductivity, electrocatalytic ability, biocompatibility, and availability of many active sites [15,16,17]. These NPs are very easy to be aggregated, inducing the deterioration of their outstanding properties and instability of GalOx immobilization [18, 19]. The disadvantages of NPs and polymers turn out that the proper materials for Gal biosensor must possess the proper physical/chemical properties and structure to guarantee the enzyme immobilization and the DET process. Our result is opening a new strategy to synthesize the novel ZnO nanostructure based on a facile, low-cost, and eco-friendly method for Gal biosensor application

Experimental

The Immobilization of the Galactose Oxidase Enzyme on

Results and Discussion

Conclusion