Human pancreatic lipase is a symbolic biomarker for the diagnosis of acute pancreatitis, which has profound significance for clinical detection and disease treatment. Herein, we first demonstrate a paper-based lipase sensor via a phase separation-induced viscosity change. Lipase catalyzes triolein to produce oleic acid and glycerol. Adding an excess of Ca2+ produces calcium oleate. The remaining Ca2+ binds with sodium alginate, triggering hydrogelation with an “egg-box” structure. The viscosity change of the aqueous solution induced by the phase separation process can be quantified by measuring the solution flow distance on a pH test paper. The paper-based lipase sensor has high sensitivity with a detection limit of 0.052 U/mL and also shows excellent specificity. Additionally, it is also utilized for quantitative lipase analysis in human serum samples to exhibit its potency in acute pancreatitis detection. This method overcomes the drawbacks of low sensitivity, slow response, and poor reproducibility caused by the nonuniform distribution of the highly viscous hydrogel on the sensing interface in existing approaches. In conclusion, thanks to the prominent characteristics of high portability, low cost, and easy operation, it is prospective for simple quantitative detection of lipase and has great potential for commercialization.
Trichlorfon, an organophosphorus pesticide widely used in agriculture and other fields, poses a severe risk to both food safety and human health. We developed a photonic crystal film sensing platform for detecting trichlorfon, a hazardous organophosphorus pesticide. The method exploits trichlorfon’s inhibition of acetylcholinesterase (AChE). Normally, AChE catalyzes acetylcholine hydrolysis to produce acetic acid, which decomposes CaCO3to release Ca2+. This triggers calcium alginate hydrogel formation, increasing solution viscosity and trapping water. When trichlorfon inhibits AChE, hydrogel formation fails, leaving the solution in a low-viscosity sol state with abundant free water. Immersing the film in trichlorfon-containing sodium alginate solutions causes water absorption and film swelling due to free water. Higher trichlorfon concentrations reduce hydrogel formation, increase free water, and amplify film swelling, resulting in proportionally higher reflectivity. The platform demonstrates a wide linear range (1–250 ng/mL) and a low detection limit (0.4 ng/mL) for trichlorfon. Successful analysis of real samples confirms its practicality for residue detection. This label-free thin-film sensor shows significant potential for monitoring trichlorfon and other organophosphorus pesticides.
危险品化学品经营许可证（带存储）