Nanozyme-Based Biofuel Cell Ingeniously Coupled with Luminol Chemiluminescence System through In Situ Co-Reactant...

Classical luminol-based chemiluminescence (CL) is the process of emitting light enhanced by the addition of coreactant hydrogen peroxide (H₂O₂). To address the instability issue of H₂O₂ decomposition, herein, we proposed a nanozyme-based biofuel cell (BFC) ingeniously coupled with a luminol CL system via in situ generation of H₂O₂. Specifically, the gold nanoparticle (AuNP) nanozyme with glucose oxidase-like activity can act as the anodic enzyme of BFC to catalyze the oxidation of glucose to produce H₂O₂ and electrons. In this case, H₂O₂ as a coreactant enhanced the CL intensity and the cathode of the BFC obtained electrons to generate the open circuit voltage (E^OCV) signals. As a result, a dual-signal biosensing platform was successfully constructed. Interestingly, the AuNPs-catalyzed system operates in an alkaline medium, which precisely meets the pH requirement for luminol luminescence. Such a BFC-CL system not only greatly lessens the effect of unstable exogenous H₂O₂ on the signal stability but also enhances the CL of luminol. Furthermore, both CL and E^OCV signals present a positive correlation with the glucose concentration. Therefore, this novel BFC-CL system shows good performance for dual-signal biosensing, which would serve as a valuable guideline for the design and application of BFC-based self-powered or CL biosensors.