Paper-based electrochemical sensors with reduced graphene nanoribbons for simultaneous detection of sulfamethoxazole and trimethoprim in water samples

Failure to control the levels of emerging pollutants in water supply can affect the quality of human life, and this maybe mitigated with a low-cost, real-time monitoring system. Herein, we describe a paper-based fully printed electrochemical sensor with reduced graphene nanoribbons (rGNR) capable of detecting sulfamethoxazole (SMX) and trimethoprim (TMP) antibiotics simultaneously in real water samples. The electrodes were printed on parchment paper, which is environmentally friendly and has an efficient printing capacity. Deposition of rGNRs in the matrix was confirmed with Raman spectroscopy, transmission electron microscopy (TEM), and X-ray photoemission spectroscopy (XPS). Optimized sensing performance was obtained using an electrochemical treatment of the electrodes at neutral pH. The paper-based sensor displayed a linear response from 1 mu mol l-1 to 10 mu mol l-1 for both antibiotics, with detection limits of 0.09 mu mol l-1 and 0.04 mu mol l-1 for SMX and TMP, respectively. The sensor was reproducible, with an RSD below 5%,and selective for the antibiotics including in real samples, in a demonstration of its potential for realtime monitoring of water supply systems.

Automated summary

A paper-based fully printed electrochemical sensor with reduced graphene nanoribbons was developed for real-time monitoring of sulfamethoxazole (SMX) and trimethoprim (TMP) antibiotics in water samples. The sensor showed a linear response from 1 to 10 mu mol l-1 for both antibiotics and had detection limits of 0.09 mu mol l-1 for SMX and 0.04 mu mol l-1 for TMP, demonstrating its potential for monitoring water supply systems.