Electrochemiluminescence shunt via bi-based co-reaction accelerator for the identification of pentanol isomers

Pentanol represents an attractive clean-burning biofuel, yet fuel commonly contain multiple structurally similar pentanol isomers that perturb the flash-point and impair combustion performance, necessitating the differentiated identification of pentanol isomers. Herein, we propose an electrochemiluminescence (ECL) shunt strategy that redirects reaction intermediates in a Bi-based bifunctional system, thereby guiding the selective cathodic or anodic ECL emission of luminol for identification of pentanol isomers. In-situ characterization and theoretical calculations reveal that Bi single atoms selectively generate hydroxyl radicals to induce cathodic ECL signal of luminol. In contrast, Bi nanoparticles generate superoxide radicals alongside the electrooxidation of luminol, which triggers an anodic ECL signal. According to the disparate radical-scavenging behaviors of pentanol isomers, a dual-channel ECL sensor array is fabricated. We demonstrate accurate classification of five pentanol isomers by combining principal component analysis clustering with a random-forest supervised-learning model.