A Sugar-Responsive Microgelzyme for Extracting Energy from Sugar Industry Wastewater

The treatment of sugar industry wastewater presents significant environmental challenges, due to its complex composition. However, enzymatic biofuel cells (EFCs), which offer a promising solution by combining wastewater treatment with bioenergy generation, remain underexplored. A key challenge involves the strict substrate specificity and stability of glucose oxidase (GOx), the most commonly used anodic enzyme, limiting its broader application. Herein, we present a sugar-responsive microgelzyme, Au/FAD@pPBA, as a mimic of promiscuous GOx with expanded substrate specificity over a wide temperature range (25.0–70.0 °C). The microgelzyme is prepared by replacing apo-GOx with poly(phenylboronic acid) (pPBA) microgels for coencapsulation of the cofactor flavin adenine dinucleotide (FAD) and gold nanoparticles (AuNPs). Experimental results reveal a synergistic effect between FAD and AuNPs within the polymer networks, enabling efficient catalytic oxidation of various sugars (e.g., glucose, mannose, xylose, galactose, and fructose), demonstrating its potential for fuel-flexible EFCs and sustainable sugar industry wastewater treatment.