Perforated graphene mediated electrochemical pollutant detection in environmental matrices: Key role of defective structure in surface enrichment, electron transfer and anodic oxidation

Perforated graphene-based electrochemical environmental sensor is developed. • Excellent performance is obtained for detecting bisphenol A in water samples. • Main detecting properties are elucidated in comparison. • A strategy to refine graphene-mediated electrochemical sensor is provided. Thermally perforated graphene (pGO) was prepared through the high-temperature alkaline etching to develop a sensitive electrochemical detecting platform for bisphenol A (BPA) in environmental waters. Abundant micro- and mesopores were generated, increasing the specific surface area from ∼50.0 to ∼300.0 m 2 ·g −1 and enhancing surface adsorption and charge-transfer properties. Compared to the graphene oxide-modified electrode, the pGO/GCE demonstrated superior electrochemical kinetics, evidenced by a significantly lower charge transfer resistance ( R ct) and a greater effective charge-selective area. These improvements facilitated more rapid interfacial electron transfer and reduce energy barriers. Furthermore, the diffusion coefficient ( D ) of pGO (15.6809 cm 2 ·s −1 ) was markedly higher than that of GO (0.4044 cm 2 ·s −1 ). Benefiting from these merits, the sensor exhibited robust and stable anodic signals, achieving a wide linear range of 0.5–50 μmol·L −1 (R 2  = 0.999), and a low detection limit of ∼10.0 nmol·L −1 (S/N = 3). Good selectivity was measured in practical applications, achieving recoveries of 95.4–100.2% in tap-water, secondary-water, surface-water, mineral-water and milk-powder samples. Introducing defects by thermal perforation improved mass transport, surface enrichment and electron transfer, offering a promising approach to develop high-performance electrochemical sensors for trace contaminants in environment. Download: Download high-res image (454KB) Download: Download full-size image