title: Colorimetric assay for heterogeneous-catalyzed lipase activity: enzyme-regulated gold nanoparticle aggregation.
abstract: Lipase is a neglected enzyme in the field of gold nanoparticle-based enzyme assays. This paper reports a novel colorimetric probe to rapidly visualize lipase activities by using Tween 20 functioned GNPs (Tween 20-GNPs) as a reporter. The present strategy hence could overcome the limitations caused by the heterogeneous interface in lipase assay. Catalytic hydrolytic cleavage of the ester bond in Tween 20-GNPs by lipase will trigger the rapid aggregation of GNPs at a high salt solution. The color change from red to purple could be used to sense the activity of lipase. The detection limit (3σ) is as low as 2.8 × 10-2 mg/mL. A preliminary enzyme activity screening was carried out for seven commercially purchased lipase samples. It also has been successfully applied to detecting lipase in fermentation broth of Bacillus subtilis without any pretreatment.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Tang
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.forename: Ling
authors.initials: L
authors.lastname: Jiang
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Feng-Wei
authors.initials: FW
authors.lastname: Huo
authors.forename: Danbi
authors.initials: D
authors.lastname: Tian
mesh_terms: D001412:Bacillus subtilis; D002384:Catalysis; D003124:Colorimetry / Q000379:methods*; D005285:Fermentation; D006046:Gold / Q000737:chemistry*; D008049:Lipase / Q000378:metabolism*; D053768:Metal Nanoparticles / Q000737:chemistry*; D011136:Polysorbates / Q000737:chemistry
chemical_list: D011136:Polysorbates; D006046:Gold; D008049:Lipase