Hydrothermal Growth of Zinc Oxide Nanorods and Glucose-Sensor Application

Kazuo Uchida,Shinji Nozaki,Surendra N Sahu,Sachindra N Sarangi

doi:10.4236/snl.2013.34a007

Abstract

High-quality zinc oxide nanorods were grown on various substrates using zinc nitrate (Zn(NO3)2) and hexamethylenetetramine ((CH2)6N4). The substrates greatly affect the hydrothermal growth of ZnO nanorods. Making the best use the substrate effect, we engineered substrates to make a single nanorod in each hole of 100 nm × 100 nm in the array of the holes on the photoresist-patterned substrate. It is also interesting to note that high-quality ZnO nanorods grown on GaN substrates by the hydrothermal growth technique have demonstrated the potential application as a glucose sensor without oxidase for the first time. The photoluminescence in the UV wavelength range was quenched by immobilizing glucose on the ZnO surface. The peak intensity decreased increased with the increased glucose concentrations. A good linearity and high sensitivity were obtained for the glucose concentrations of 0.5-30 mM in the calibration curve. The calibration curve was not influenced by the presence of bovin serum albumin (BSA), ascorbic acid (AA) and uric acid (UA), which are also included in human blood and could cause interference in estimating glucose concentrations in human blood. The PL quenching was attributed to the H2O2 molecules, which were produced by the photo-oxidation of glucose during exposure to UV light. The PL-quenching glucose sensor made of ZnO nanorods has been evaluated for the first time by estimating the glucose concentrations in the human serum samples which include those of diabetes, and a good correlation was obtained between the concentrations by the PL quenching and the clinical data provided by a local hospital.

Highlights

Zinc oxide ZnO nanorods have attracted the increasing attention because of their wide variety of electronic and photonic device applications as a wide band gap semiconductor
We report non-enzymatic glucose sensing by PL emission quenching technique in ZnO nanorods and discuss their potential application as a glucose biosensor using β-D-glucose
One single nanorod was successfully grown by the hydrothermal growth technique in every hole of the photoresist-patterned GaN when the hole size was 200 nm × 200 nm or less and the solution concentration was reduced to 5 mM

Summary

Introduction

Zinc oxide ZnO nanorods have attracted the increasing attention because of their wide variety of electronic and photonic device applications as a wide band gap semiconductor. ZnO nanorods have great application potential in the field of biosensors due to their excellent biocompatibility, optical property, non-toxicity, chemical and electrochemical stability, high electron communication features and large specific surface area. Most of them are based on enzymatic and electrochemical techniques These sensors are limited to their calibration range, biosensor response time, lifetime, stability etc. The luminescence quenching is usually understood in terms of the electron transfer reaction from the photo-excited particles to electron absorbing acceptors It suggests that electron or hole acceptors adsorbed at the surface of nanostructures can change their luminescence properties and quench the exciton emission by fast electron transfer. We report non-enzymatic glucose sensing by PL emission quenching technique in ZnO nanorods and discuss their potential application as a glucose biosensor using β-D-glucose

Experimental

Results and Discussion

Conclusion