Deep eutectic solvents (DESs) are an emerging class of green solvents formed by mixing hydrogen bond donors and acceptors in specific ratios, resulting in a highly structured hydrogen-bond network. When embedded into a polymeric matrix, they give rise to eutectogels (EGs)—hybrid materials that combine the tunable chemical environment of DESs with the mechanical strength and flexibility of hydrogels. These properties make EGs promising candidates for biotechnological applications, including biosensing.

DESs have demonstrated the ability to enhance enzyme solubility, stability, and activity, opening new avenues for their use in biocatalysis and biosensor design. However, their integration into functional biosensing platforms remains underexplored. In this work, we report the development of a versatile biosensor based on EGs incorporating pancreatic lipase (PL), aimed at detecting lipase inhibitors with potential anti-obesity effects.

PL was selected as a model enzyme due to its central role in lipid digestion and its relevance as a therapeutic target for obesity. The enzyme was solubilized in various DES formulations, and its catalytic activity and structural stability were evaluated using intrinsic fluorescence spectroscopy. EGs were subsequently synthesized via UV-initiated radical polymerization, allowing efficient enzyme entrapment within the gel matrix.

The biosensor was successfully validated using orlistat, a clinically approved PL inhibitor, demonstrating its potential for anti-obesity drug screening. Importantly, this platform is adaptable and can be extended to other enzymes and therapeutic targets, highlighting its broader applicability in drug discovery and biosensing.