title: A simple and universal "turn-on" detection platform for proteases based on surface enhanced Raman scattering (SERS).
abstract: We describe herein a novel' "turn-on" SERS-based strategy for protease detection based on surface enhanced Raman scattering (SERS) and the mediation of spacing between 4-mercaptobenzoic acid (4-MBA) labeled gold nanoparticles (AuNPs) through enzyme assays. The method employed non-cross-linking aggregation of 4-MBA-modified AuNPs by peptides after treatment with target protease. Thus, SERS signals of 4-MBA are sharply increased because of the decreased electrostatic stability of AuNPs that initiated gold nanoaggregates incorporating Raman reporter molecules due to the formation of "Hot Spots". Through this strategy, a novel and facile "turn-on" SERS biosensor for trypsin and thrombin based on enzymatic cleavage activity is established with sensitivity, selectivity and simplicity as AuNPs and peptides are easily accessible. Compared with other methods, this newly proposed method has improved sensitivity. The limit of detection was 85fM (at the ratio of signal to noise, S/N=3:1) for trypsin. Controlled experiments showed that the method exhibited good selectivity over other proteases. We also proved that this principle could be easily adapted to detection of other proteases such as thrombin. The method demonstrated the capability for application in complex matrix samples. The results also presented the potential and superiority of SERS biosensor as a general approach for proteases based on enzyme activity.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of chemistry & Molecular sciences, Wuhan University, Wuhan 430072, China.
authors.forename: Zitong
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of chemistry & Molecular sciences, Wuhan University, Wuhan 430072, China.
authors.forename: Yifei
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of chemistry & Molecular sciences, Wuhan University, Wuhan 430072, China.
authors.forename: Yizhen
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of chemistry & Molecular sciences, Wuhan University, Wuhan 430072, China.
authors.forename: Huaming
authors.initials: H
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of chemistry & Molecular sciences, Wuhan University, Wuhan 430072, China.
authors.forename: Aiguo
authors.initials: A
authors.lastname: Shen
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of chemistry & Molecular sciences, Wuhan University, Wuhan 430072, China. Electronic address: zhouxd@whu.edu.cn.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of chemistry & Molecular sciences, Wuhan University, Wuhan 430072, China. Electronic address: jmhu@whu.edu.cn.
authors.forename: Jiming
authors.initials: J
authors.lastname: Hu
mesh_terms: D057075:Enzyme Assays / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D010447:Peptide Hydrolases / Q000032:analysis* / Q000097:blood; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties; D013917:Thrombin / Q000032:analysis; D014357:Trypsin / Q000032:analysis / Q000097:blood
chemical_list: D006046:Gold; D010447:Peptide Hydrolases; D014357:Trypsin; D013917:Thrombin
keywords: Gold nanoparticles; Protease; SERS; Universal