A simple microfluidic redox cycling-based device for high-sensitive detection of dopamine released from PC12 cells

Abstract

Here, ITO electrodes modified with Au nanoparticles (AuNPs) were used to fabricate a microfluidic redox cycling-based chip device (AuNPs-MRECD) for highly sensitive and selective electrochemical detection of dopamine (DA). Briefly, ITO electrodes, each with a ∼ 3.2 × 3.2 mm2 working area, were fabricated using photolithography and dry etching processes. Afterward, the electrodes were modified with Au nanoparticles (AuNPs) electrochemically and used in the assembly of AuNPs-MRECD, in which case one AuNPs-ITO was mounted on top of another using a PET film spacer, which also defined the microfluidic channel of the device. According to the results, AuNPs-MRECD exhibited an excellent redox cycling efficiency with an amplification factor (Af) of 4.22 and a collection efficiency (Ce) of 93.7 %. Next, AuNPs-MRECD was tested for sensitive and selective detection of DA; where the device displayed an LOD of 27.9 nM over a linear detection range of 50 to 1000 nM based on reduction current. Finally, the device was successfully applied to the detection of DA released from PC12 cells, suggesting that the device is a promising tool for evaluating dopaminergic cells and the effects of dopaminergic drugs.