title: Gold nanoparticle coupled with fluorophore for ultrasensitive detection of protamine and heparin.
abstract: Here we report a novel label-free fluorescent sensor for ultrasensitive detection of protamine and heparin based on the high quenching ability of gold nanoparticles to the fluorescence of fluorescein. The fluorescence was significantly quenched when fluorescein molecules were attached to the surface of gold nanoparticles by electrostatic interaction. Upon addition of protamine, the fluorescein molecules were detached from the surface of the gold nanoparticles due to the stronger adsorption of protamine on the surface of AuNPs, and resulting in the recovery of the fluorescein molecules fluorescence. Heparin is able to bind with Protamine specifically. In the presence of heparin, the interaction of heparin with protamine makes the AuNPs de-aggregate and the fluorescein molecules re-attach to the AuNPs, which lead to marked fluorescence quench again. By measuring the changes in the fluorescence of the fluorescein molecules, the concentration of protamine and heparin were sequentially determined. The linear response range was obtained over the concentration range from 0 to 0.8 μg/mL and 4 to 1.6 μg/mL with the low detection limit 0.0067 μg/mL and 0.0013 μg/mL for protamine and heparin, respectively.
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Jiangna
authors.initials: J
authors.lastname: Zhao
authors.forename: Yinhui
authors.initials: Y
authors.lastname: Yi
authors.forename: Naxiu
authors.initials: N
authors.lastname: Mi
authors.forename: Bangda
authors.initials: B
authors.lastname: Yin
authors.forename: Mingjie
authors.initials: M
authors.lastname: Wei
authors.forename: Qiong
authors.initials: Q
authors.lastname: Chen
authors.forename: Haitao
authors.initials: H
authors.lastname: Li
authors.forename: Youyu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D001667:Binding, Competitive; D019793:Fluorescein / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006493:Heparin / Q000097:blood*; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D011479:Protamines / Q000097:blood*; D012996:Solutions; D013050:Spectrometry, Fluorescence; D055672:Static Electricity
chemical_list: D005456:Fluorescent Dyes; D011479:Protamines; D012996:Solutions; D006046:Gold; D006493:Heparin; D019793:Fluorescein
keywords: Fluorescein; Fluorescent sensor; Gold nanoparticle; Heparin; Protamine