Environmental contextBisphenol A is an endocrine disruptor, which may migrate and transfer to the environment where it presents a potential risk to the health of humans and animals. Herein, we demonstrate that electrospun nanofibers could be used to develop a highly efficient solid-state quenching sensor for on-site determination of bisphenol A in river water samples. The strategy has great potential for routine environmental analyses. AbstractA novel solid-state electrochemiluminescence (ECL) quenching sensor based on luminescent composite nanofibres for detection of bisphenol A (BPA) has been designed. Luminescent composite nanofibres of ruthenium(ii) tris(bipyridine) (Ru(bpy)(3)(2+))-doped core-shell Cu@Au alloy nanoparticles (Ru/Cu@Au) mixed with nylon 6 (PA6)-amino-functionalised multi-walled carbon nanotubes (MWCNTs), Ru/Cu@Au-MWCNTs-PA6, were successfully fabricated by a one-step electrospinning technique. The Ru/Cu@Au-MWCNTs-PA6 nanofibres, with a unique 3D nanostructure, large specific surface area and double Ru(bpy)(3)(2+)-ECL signal amplification, exhibited excellent ECL photoelectric behaviours on a glassy carbon electrode. As a solid-state ECL sensor, the Ru/Cu@Au-MWCNTs-PA6 nanofibres can sensitively detect low concentrations of BPA by monitoring the BPA-dependent ECL intensity change. The detection limit for BPA is 10 pM, which is comparable or better than that in the reported assays. The sensor was successfully applied to on-site determination of BPA in river water samples obtained from eight different sampling sites with good recovery, ranging from 97.8 to 103.4%. The solid-state ECL sensor displayed wide-range linearity, high sensitivity and good stability, and has great potential in the field of environmental analyses.