title: Gold nanoparticle-based colorimetric assays for coagulation-related proteins and their inhibition reactions.
abstract: In this paper, we describe two simple, label-free, homogenous assays using gold nanoparticles (Au NPs)-one to detect coagulation-related proteins and the other to screen inhibition reactions. The first nanosensor functions on the basis of the fact that thrombin catalyzes fibrinogen to form long-chain fibrins, which then induce aggregation of Au NPs. We applied this sensor to study the interactions of thrombin, inhibitors, cofactors, and antidotes. We further used thrombin-conjugated Au NPs (Thr-Au NPs) to analyze the levels of fibrinogen in plasma samples via fibrinogen-induced aggregation of Thr-Au NPs. The limit of detection (LOD; S/N=3) of this sensor for fibrinogen in plasma was 10nM. The Thr-Au NP probe provided quantitative results for fibrinogen in plasma samples that correlated (R(2)=0.97) with those obtained using a clinical von Clauss clotting rate assay. In addition, the Thr-Au NP-based sensor could be used to monitor thrombin concentrations in plasma samples under physiological conditions. Compared with conventional assays, these label-free assays offer several advantages, such as rapid and simple readout by the naked eye or by UV-vis absorption spectroscopy.
authors.affiliation: Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Yi-You
authors.initials: YY
authors.lastname: Chen
authors.forename: Chao-Wei
authors.initials: CW
authors.lastname: Tseng
authors.forename: Hsin-Yun
authors.initials: HY
authors.lastname: Chang
authors.forename: Yu-Lun
authors.initials: YL
authors.lastname: Hung
authors.forename: Chih-Ching
authors.initials: CC
authors.lastname: Huang
mesh_terms: D000328:Adult; D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry / Q000191:economics / Q000379:methods*; D005340:Fibrinogen / Q000032:analysis* / Q000378:metabolism; D006046:Gold / Q000737:chemistry; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry; D012680:Sensitivity and Specificity; D013917:Thrombin / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000378:metabolism; D055815:Young Adult
chemical_list: D006046:Gold; D005340:Fibrinogen; D013917:Thrombin