title: Highly sensitive real-time assay of inorganic pyrophosphatase activity based on the fluorescent gold nanoclusters.
abstract: On the basis of the competition assay approach and fluorescent 11-mercaptoundecanoic acid-capped AuNCs (AuNCs@11-MUA) with unique optical properties, a convenient, reliable and highly sensitive real-time assay of pyrophosphatase (PPase) activity is established and developed for the first time. Pyrophosphate (PPi) could recover the Cu(2+)-quenched AuNCs@11-MUA fluorescence selectively owing to the higher binding affinity between PPi and Cu(2+) than that between 11-MUA and Cu(2+). Whereas PPase could catalyze the hydrolysis of PPi, thus released Cu(2+), leading to fluorescence requenching of the AuNCs@11-MUA. In the assay, a good linearity between the fluorescence response and PPase activity within a range from 1 to 20 mU is found, with a detection limit of less than 1 mU, which is better than other PPase assays using PPi as the substrate. Additionally, we demonstrate that our AuNCs@11-MUA-based fluorescent assay can be applied to assay the PPase activity in real biological samples such as the cell lysate. This strategy paves a new avenue for exploring the sensing applications of fluorescence AuNCs and improving the development of competition assay approach.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, Jilin 130022, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.forename: Dan
authors.initials: D
authors.lastname: Zhao
authors.forename: Xiurong
authors.initials: X
authors.lastname: Yang
mesh_terms: D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles; D046529:Microscopy, Electron, Transmission; D011755:Pyrophosphatases / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D006046:Gold; D011755:Pyrophosphatases