title: A "turn-off" SERS-based detection platform for ultrasensitive detection of thrombin based on enzymatic assays.
abstract: Herein we describe a novel "turn-off" biosensing strategy for thrombin detection based on Surface Enhanced Raman scattering (SERS) and the mediation of spacing between 4-mercaptobenzoic acid (4-MBA) labeled gold nanoparticles (AuNPs). The multiple arginine peptides that initiated gold nano-aggregates incorporating Raman reporter molecules due to the formation of "Hot Spots", are induced to disband by the addition of thrombin in which the peptides are catalytically cleaved into fragments and thus SERS signals of 4-MBA are sharply declined because of the weakened ability of fragments to induce aggregation. Through this strategy, a novel "turn-off" SERS biosensor for thrombin based on enzymatic amplification is established with sensitivity, selectivity and simplicity as AuNPs and peptides are easily accessible. Compared with non-enzymatic amplification based methods, this newly proposed method has improved sensitivity. The limit of detection was 160 fM (at the ratio of signal to noise, S/N=3:1). Further, controlled experiments showed that the method exhibited good selectivity over other proteases. The method demonstrated the capability and the potential for application in complex matrix and future biomarker development. The results also presented the potential and superiority of SERS biosensor based on signal amplification.
authors: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry & Molecular Sciences, Wuhan University, Wuhan 430072, China.
authors: Zitong
authors: Z
authors: Wu
authors: Yizhen
authors: Y
authors: Liu
authors: Xiaodong
authors: X
authors: Zhou
authors: Aiguo
authors: A
authors: Shen
authors: Jiming
authors: J
authors: Hu
mesh_terms: D001565:Benzoates / Q000737:chemistry* / Q000378:metabolism; D015374:Biosensing Techniques / Q000379:methods; D057075:Enzyme Assays / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry*; D010455:Peptides / Q000378:metabolism*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000737:chemistry* / Q000378:metabolism; D013917:Thrombin / Q000032:analysis* / Q000378:metabolism
chemical_list: D001565:Benzoates; D010455:Peptides; D013438:Sulfhydryl Compounds; C013594:4-mercaptobenzoate; C015462:polyarginine; D006046:Gold; D013917:Thrombin