Rationally engineered cyano-modified graphite carbon nitride for enhanced electrochemiluminescence and sensitive...

Perfluoroalkyl and polyfluoroalkyl substances, a class of synthetic chemicals extensively employed in industrial manufacturing and consumer products, have emerged as globally concerning persistent organic pollutants. Among them, perfluorooctanoic acid (PFOA) is a persistent environmental contaminant that exhibits bioaccumulative properties and toxicity, thereby posing severe threats to human health and ecological systems. Although methods such as high-performance liquid chromatography-tandem mass spectrometry provide accurate quantification, they are hindered by high cost, complex operation, and unsuitability for on-site applications. Consequently, the development of an efficient analytical method for PFOA detection in environmental water bodies is of paramount importance, bearing urgent practical significance for environmental risk assessment and pollution remediation.

In this study, a novel molecularly imprinted polymer (MIP)-based "signal-off" electrochemiluminescence (ECL) sensor was proposed for sensitive detection of PFOA. The ECL performance of graphitic carbon nitride (CN) was significantly enhanced through rational engineering of cyano group content in CN via an alkali-assisted modulation strategy. Mechanism investigation confirmed that the incorporation of cyano group into CN nanosheets improves electron conductivity, increases charge carrier density, and accelerates electron-hole recombination kinetics, thereby enhancing the ECL strength and stability of CN nanosheets. To achieve specific PFOA detection, a MIP-based ECL sensor (MIP@CCN-0.03g) was constructed by electrochemical polymerization of pyrrole on the CCN-0.03g-modified GCE using PFOA as the template. The prepared ECL sensors exhibited excellent analytical performance, with a linear range of 0.02 to 400 ng/mL for PFOA and a detection limit of 0.009 ng/mL.

This work provides a novel strategy to enhance CN-based ECL performance via cyano modification and develops a practical sensor for on-site PFOA monitoring. The design of this sensor not only provides fundamental insights into the role of cyano groups in enhancing ECL but also offers a robust and efficient sensing platform for environmental monitoring applications.