Boron doped graphitic carbon nitride modified interface for electroanalysis of hazardous p-benzoquinone in water

Abstract

Parabenzoquinone (PBQ), a benzene derivative, is an emerging micro-pollutant known for its cytotoxicity. Its anthropogenic presence in air and water bodies and extremely high reactivity with biological metabolites make it a toxic pollutant. Exposure to PBQ can lead to respiratory disorders, cancer, and cellular apoptosis. Consequently, monitoring the trace level of PBQ in air, groundwater, and industrial wastewater is crucial. Therefore, this work intends to develop an electrochemical sensor for assaying PBQ using boron-doped graphitic carbon nitride (B-gCN) as a metal-free and sustainable recognition element. B-gCN is chosen to exploit the specific interaction between gCN and PBQ, majorly, the π-π stacking and the hydrogen bonding. Compared to conventional drop-casting, electrodeposition has been opted for the efficient immobilization of nano-scale microporous B-gCN layer on the electrode surface. The modified surface has been well characterized using microscopic and spectroscopic tools. The electroactivity of PBQ on the B-gCN modified interface has been examined using cyclic voltammetry and square wave voltammetry, which demonstrate substantial electro-catalytic activity. The modified interface exhibited 122 times higher sensitivity for PBQ oxidation than bare GCE with a LOD of 22.5 nM in a linear concentration range of 1.0–500.0 µM. The sensor showcased excellent selectivity in the presence of metal salts and organic pollutants. Furthermore, promising results were observed in environmental samples such as river water (Ganga water), tap water, and RO wastewater with < 6 % error margins. The developed sensor also demonstrated excellent stability, reproducibility, and repeatability, indicating the ability of the proposed approach to be used for on-field, direct environmental analysis. © 2025 Elsevier Ltd