Portable microfluidic chip electrophoresis device with integrated Pt electrodes for the analysis of AgNPs.

A portable electrophoresis device based on the SU-8/Pyrex microfluidic chip with integrated three 100 µm platinum (Pt) thin-film electrodes (working, reference, and auxiliary) was adapted for the analysis of silver nanoparticles (AgNPs). The microfluidic platform includes the main electrophoresis instrument, reusable holder, and microfluidic chip with integrated Pt electrodes. The electrochemical oxidation behaviours of AgNPs on Pt thin-film electrode were investigated by using cyclic voltammetry, while the electrophoresis behaviours of AgNPs were studied on the 'Lab-on-a-chip' platform. The influences of parameters including running buffer, separation voltage, and detection potential on the electrophoresis behaviours of AgNPs were all investigated. The results showed that AgNPs could be oxidised at 0.2-0.4 V [phosphate buffer solution buffer, pH 7.0] on the Pt thin-film electrode. The peak current enhanced with the increase of separation voltage, while the retention time decreased. The peak current varied with the detection potential and reached the highest value at 0.4 V. This microfluidic platform could be a fast and portable detection system for the analysis of total AgNPs. [ABSTRACT FROM AUTHOR]