Self-Powered, Sensitive Photoelectrochemical Determination of Hydrogen Peroxide Using Cellulose Based Coupling of <i>Lactobacillus acidophilus</i> with a NiFe Layered Double Hydroxide (LDH) Heterojunction

Cellulose (CEL), a large polysaccharide composed of glucose units, is indigestible in the human gastrointestinal system due to the absence of cellulase. This study has resented a pioneering approach to the photoelectrochemical (PEC) direct decomposition of CEL, employing a novel lactobacillus acidophilus/NiFe layered double hydroxide (LA/LDH) composite. This composite was synthesized <i>via</i> a simple two-step hydrothermal method, resulting in a highly effective catalyst. Remarkably, LA/LDH demonstrated complete decomposition of cellulose into carbon dioxide, attributed to the potent oxidative capability of photo-excited holes in the valence band of LA/LDH. Leveraging this decomposition, the highly sensitive PEC sensor based on the LA/LDH-CEL interface, achieved dual linear response ranges from 0.5 to 200 μM and 200 to 1400 μM, and an impressive detection limit of 0.16 μM for hydrogen peroxide (H₂O₂). The LA/LDH-CEL photoelectrode exhibits outstanding stability and sensitivity, underscoring its potential as a powerful tool for advanced PEC analysis and environmental monitoring. This work not only expands the frontiers of cellulose decomposition but also opens new avenues for developing sustainable, high-performance PEC sensors.