Martinez-Baquero_2025_Biosensors.(Basel)_15_

Eutectogels are advanced gel-based systems that integrate deep eutectic solvents (DES) into polymer networks. In this study, we report the first detailed characterization of an enzyme-containing eutectogel, representing a significant step toward advanced biosensing and biocatalytic applications. Specifically, we have incorporated pancreatic lipase, one of the main target enzymes in the treatment of obesity, in eutectogels via UV-induced radical polymerization of suitable precursors in appropriate DESs. Prior to immobilization, the enzyme was solubilized in selected DESs and its activity and conformational stability were evaluated using colorimetry and intrinsic fluorescence. Combinations of choline chloride/glycerol and tetramethylammonium chloride/glycerol were shown to be effective media for preserving and enhancing enzymatic function and conformational stability. The enzyme immersed in eutectogel exhibited high structural integrity and excellent thermal stability, maintaining its activity over several weeks. The ability of this new material to screen enzyme inhibitors was assessed using orlistat, a well-established anti-obesity agent. The results demonstrated clear detection of the drug's inhibitory effect, even at nanomolar concentrations, highlighting the material's potential as a screening platform for novel inhibitors with prospective anti-obesity activity. Furthermore, the device proved effective in quantifying drug presence, offering a promising and highly sensitive tool for pharmaceutical quality control applications.