Monitoring Antipsychotic Drug Effects on Stimulated Dopamine Release Using Carbon Nanotube Transistors with Nafion-Radical Hybrid Films

We developed floating electrode-based carbon nanotube biosensors for the monitoring of antipsychotic drug effects on the dopamine release from nerve cells (PC12) under potassium stimulation. In this work, carbon nanotube field-effect transistors with floating electrodes were functionalized with nafion films containing 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS●) radicals to build selective biosensors for the dopamine detection. The selective interaction between ABTS● radicals and dopamine allowed us to discriminate dopamine from the simultaneous presence of other neurotransmitters such as glutamate and acetylcholine with a detection limit down to 10 nM. Furthermore, we demonstrated the real-time monitoring of dopamine release from PC12 cells under the stimulation of potassium solutions at various concentrations. Significantly, we could also evaluate the effects of antipsychotic drug (pimozide) on the dopamine release from potassium-stimulated PC12 cells. Since our method enables the quantitative and real-time evaluation of drug effects on living cells, it should be a versatile tool for both biomedical researches and applications.