Development of surface droplet evaporation-based sensing platform for screening lipase inhibitors

• Published in: Microchemical journal 2024-10, Vol.205, p.111256, Article 111256
• Main Authors: Mu, Chongyang, Khan, Mashooq, Liu, Jinpeng, Dong, Xinfeng, Wang, Zhengtong, Song, Ping, Hu, Qiongzheng, Yu, Li
• Format: Article
• Language: English
• Subjects: Droplet; Enzymatic reaction; Evaporation; Portable device; Surfactant
• ISSN: 0026-265X
• DOI: 10.1016/j.microc.2024.111256

The surface droplet evaporation-based sensing platform for the screening of a lipase inhibitor orlistat based on measuring the area of aqueous droplet from the lipase-mediated enzymatic reaction. [Display omitted] •A surfactant-mediated surface droplet evaporation-based biosensor is developed.•It shows excellent performance for screening lipase inhibitors, with an IC50 value of 0.59 ± 0.09 μM for orlistat.•The sodium oleate produced by lipase digestion of triacylglycerols reduces surface tension and increases the dried area on the surface.•Olistat inhibits lipase activity and reduces the dried area on the surface.•It also works well with a portable microscope and a smartphone interface for data analysis. The development of new types of sensing platforms with excellent performance is always appealing. In this report, we demonstrate a low-cost and user-friendly sensing platform based on drying of the aqueous droplet on the surface. The principle relies on the transduction of the surfactant concentration into the area of the dried droplet on the surface. The screening of a lipase inhibitor is demonstrated as an example. When triacylglycerols (GT) and lipase are mixed, the aqueous droplet produces a large dried area on the surface. This phenomenon is attributed to the production of sodium oleate due to the enzymatic digestion of GT by lipase. It results in reduction of the surface tension and causes wetting and spreading of the droplet, leaving a large dried area on the surface. However, in the presence of orlistat, a lipase inhibitor, a small dried area is obtained due to the inhibition of lipase activity by orlistat. Using this method, the lipase inhibitor can be readily and effectively screened. Compared to previous studies, this method is simple, rapid, low-cost and avoids the use of labelled molecules and complex instrumentation, with an IC50 value of 0.59 ± 0.09 μM for orlistat. In addition, it also works well with a portable microscope and a smartphone interface for data analysis. Overall, this study provides a new method for rapid and cost-effective screening of lipase inhibitors.