Miniaturized Platform With Nanocomposite Optimized Pencil Electrodes for Selective Non-Interfering Electrochemical Sensing

Herein, a simple, miniaturized and low-cost electrochemical sensing platform integrated with three-electrode system has been presented. A two-layer microfluidic device has been fabricated entirely on a PMMA sheet using a CO2 laser. Pencil graphite electrode (PGE), chemically modified electrode with a nanocomposite of MWCNT@polysterene-chitosan (PGE/MWCNT@PS-CS) as a working electrode (WE), PGE coated with Ag/AgCl ink as a reference electrode (RE) and a plain PGE as a counter electrode (CE) were inserted into the microreactor with reagent consumption of 2 mL. As a proof of concept, the analytical performance of the developed microfluidic electrochemical sensor was investigated for non-enzymatic glucose sensing. Highly selective, non-interfering sensing of glucose in presence of various bioanalytes, was obtained. The nanocomposite lead to an exceptional limit of detection as 0.309 nM. With fine-tuning and electrode surface modification, the designed miniaturized platform could be used for diverse electrochemical biosensing application.