Pt nanoparticle decorated carbon nanotubes nanocomposite based sensing platform for the monitoring of cell-secreted dopamine

Development of reliable sensors for real-time quantification of dopamine is highly essential to understand various biological processes and still remains challenge. Here, we proposed a novel and ultrasensitive electrochemical sensing platform for the monitoring of cell-secreted dopamine based on Pt nanoparticles (PtNPs) decorated multi-wall carbon nanotubes (MWCNTs) nanocomposite, which is synthesized by in-situ reduction of platinum on poly (diallyldimethylammonium chloride) (PDDA) functionalized MWCNTs. The unique structure of the hybrid nanocomposite and the interconnectivity between PtNPs and carbon nanotubes endow the nanocomposite with the enhancing conductivity and electrochemical activity. The Pt-MWCNTs hybrid modified screen-printed electrode exhibited excellent electrocatalytic ability for the detection of dopamine with a wide linear range (5 nM to 1 μM) and a low detection limit (2 nM). The developed sensor enables the real-time recording of dopamine released from PC12 cells induced by the stimulation of K+ saline. Also, this approach can be used to quantitatively evaluate the effects of antipsychotic drug (aripiprazole) on the dopamine release from cells treated with high K+. Results indicated that the sensor could provide an effective tool for the monitoring of extracellular neurotransmitters related to the exogenous agent and drug on the nervous system.