Multi-dimensional multi-level sensing nanostructure for high-performance detection to trace-level dopamine molecules

A novel multi-dimensional nanostructure constructed with three types of nano-building-block is used as electrochemical sensing material to detect trace dopamine which plays as neurotransmitter in body-fluids. For the multi-dimensional multi-level sensing nanostructure construction, nanosheet of graphene oxide (GO) is herein served as nano-substrate. By using hydrothermal method, ZnO nanowires are well-aligned grown on the GO nano-substrate. The nanoporous ZIF-8 (a subclass of metal-organic frameworks) is subsequently grown on the surface of ZnO via a chemical vapor deposition (CVD) process. The electrochemical sensing measurements indicate that the detection limit of the sensor to dopamine reaches sub-nM level.

Introduction

As one of the most important neurotransmitters, dopamine (DA) plays a vital role in the central nervous, cardiovascular, renal and hormonal systems [1]. Low concentration of DA may cause neurological disorders like schizophrenia and Parkinson disease. Thus, it is greatly meaningful to measure the DA concentration in biological systems. Nowadays the detection of DA is mainly based on bulky instruments such as spectrophotometry, liquid chromatography and capillary electrophoresis. Generally, the currently available DA detection instruments are expensive, bulky, time-consuming and labor-intensive. In contrast, high performance chemical sensors are promising for portable detection of low concentration DA [2]. Although various chemical sensors have been developed for DA detection, it is still a big challenge to selectively detect DA at ultra-low concentration due to the complicated detection environment of body-fluids like blood and urine. To realize high performance DA detection, novel sensing material integrated with multi-functions for specific capturing and sensing targeted molecules is highly demanded.