Lab-made screen-printed electrode with conductive ink based on carbon nanomaterials for simultaneous electrochemical analysis of bisphenol A, catechol, and 4-nitrophenol

Disposable, flexible, and low-cost, lab-made screen-printed electrodes (SPEs) using conductive inks based on carbon nanomaterials were applied to determine environmental pollutants in water. Several compositions of carbon conductive inks were investigated, and the best one was composed of nanographite, graphene nanoplatelets, and alkyd resin (40:10:50%, w/w/w). Under optimized conditions using square wave voltammetry, calibration curves were constructed (individually and simultaneously) for detection of bisphenol A (BPA), catechol (CC), and 4-nitrophenol (4-NP), presented linear responses in the 2.5 to 200 µmol L-1 range. From the individual curves, the LODs obtained for BPA, CC, and 4-NP were 1.7, 6.9, and 2.8 µmol L-1, respectively. The proposed sensors were chemically and microscopically characterized and evaluated for their analytical performance, including stability (over 70 days, with RSD < 10%), reproducibility (RSD < 10% for 10 SPEs), possible interferences (relative error < 12%), and hazardous phenolic pollutants on-site analysis in water samples (RE < 10%).