Thread-Based Fluidic Platform with Pencil Graphite Electrodes For Electrochemical Analyzing Medicine Metabolites in Urine

This study develops a thread-based fluidic platform for electrochemical analysis of acetaminophen metabolism in urine samples. Low-cost yet high sensing performance produced with 0.3-mm commercial pencil graphite electrodes (PGEs) mounted on a designed 3D printed slidable stages are adopted for the electrochemical detection of the sample separated on the polyester thread. Therefore, the gaps between the electrochemical electrodes are adjustable and the sensing performance can be enhanced. Moreover, the PGEs can also be rapidly renewed if damaged or contaminated. Experimental results show that the PGEs exhibited nice electrochemical responses after the oxygen plasma treatment compared to the surface treatments of acid or base pickling. A common medicine of acetaminophen of different concentrations is successfully analyzed with the developed PGEs in the spiked human urine samples. The developed thread-based fluidic platform has shown its potential in rapidly detecting drug metabolites in urine.