Gold Nanoparticles Sensitized ZnO Nanorods Arrays for Dopamine Electrochemical Sensing

One-dimensional nanostructure materials offer opportunities for improving performance of electrochemical sensors. In this work, vertically ZnO nanorods (ZNRs) sensitized with gold nanoparticles (GNPs) were designed and fabricated onto indium tin oxide coated polyethylene terephthalate (ITO/PET) film for dopamine sensing. ZNRs that helpful for electric signal collecting by providing electron transfer pathways were electrodeposited on ITO/PET film firstly. Then GNPs that possess excellent electrocatalytic activity toward target were decorated onto ZNRs via potentiodynamic electrodeposition. These gold nanoparticles sensitized ZnO nanorods arrays (GNPs/ZNRs) combine the advantages of GNPs and ZNRs, thus providing chance to develop electrochemical sensors with ultrahigh sensitivity and excellent selectivity. Several important nervous system diseases (such as Parkinson's disease, schizophrenia, senile dementia, AIDS, et al.) have proved to be associated with dysfunctions of dopamine system. So, the detection of dopamine becomes essential in clinical medical practice and nerve physiology study. When used for dopamine sensing, the fabricated electrochemical sensor shows two linear dynamic ranges (0.01–20 μM and 50–1000 μM) toward dopamine. Moreover, this proposed electrochemical sensor has been successfully applied to the determination of dopamine in human urine with satisfied recoveries (95.3% to 111.3%) and precision (1.1% to 8.4% of RSD).