MWCNTs/Ag-enhanced Molecularly Imprinted Resorcinol Polymer Voltammetric Sensing Platform for Dopamine Determination

Abstract The most prevalent catecholamine neurotransmitter of brain, dopamine (DA), is crucial to the operation of the hormone, blood vessel, and central nervous system systems. The effective determination of dopamine by means of advanced, efficient, and sensitive determination techniques has attracted much attention. This experiment designed and prepared a molecularly imprinted electroanalytical determination platform for the determination of DA. In this work, silver nanoparticles (Ag NPs) were in-situ carried on the walls of multiwalled carbon nanotube (CNTs) using sodium borohydride (NaBH4) as a reducing agent. The CNTs/Ag/GCE altered electrode was prepared using a simple drop-casting method. Molecularly imprinted polymer (MIP) membranes towards recognizing DA molecules were prepared on altered electrode surfaces using electropolymerization using resorcinol as the functional unit and dopamine (DA) as the template molecule. The cooperative effect of Ag and CNTs boosted the conductivity as well as the electrocatalytic efficiency, thereby enhancing the sensitivity to electrochemical response of the platform and reducing the determination limit. After optimizing the parameters, including the proportion of templates to functional units, electropolymerization cycles, incubation time, and pH, the platform's linear determination range for DA was 0.008 - 0.1 μM and 3 - 100 μM, with a 0.003 μM determination limit. Additionally, the platform exhibits great selectivity, anti-interference, and reproducibility. The sample recovery rate for spiked real samples, urine and serum, was good. This study provides a reference for the extraction, separation, and determination of DA.