title: Electrostatic interaction based approach to thrombin detection by surface-enhanced Raman spectroscopy.
abstract: We have developed an electrostatic interaction based biosensor for thrombin detection using surface-enhanced Raman spectroscopy (SERS). This method utilized the electrostatic interaction between capture (thrombin aptamer) and probe (crystal violet, CV) molecules. The specific interaction between thrombin and aptamer could weaken the electrostatic barrier effect from the negative charged aptamer SAMs to the diffusion process of the positively charged CV from the bulk solution to the Au nanoparticle surface. Therefore, the more the bound thrombin, the more the CV molecules near the Au nanoparticle surface and the stronger the observed Raman signal of CV, provided the Raman detections were set at the same time point for each case. This procedure presented a highly specific selectivity and a linear detection of thrombin in the range from 0.1 nM to 10 nM with a detection limit of about 20 pM and realized the thrombin detection in human blood serum solution directly. The electrostatic interaction based technique provides an easy and fast-responding optical platform for a "signal-on" detection of proteins, which might be applicable for the real time assay of proteins.
authors.affiliation: State Key Laboratory of Chem/Biosensing and Chemometrics, Chemistry and Chemical Engineering College, Hunan University, 410082 Changsha, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Hu
authors.forename: Peng-Cheng
authors.initials: PC
authors.lastname: Zheng
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Jiang
authors.forename: Guo-Li
authors.initials: GL
authors.lastname: Shen
authors.forename: Ru-Qin
authors.initials: RQ
authors.lastname: Yu
authors.forename: Guo-Kun
authors.initials: GK
authors.lastname: Liu
mesh_terms: D052158:Aptamers, Peptide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods; D005840:Gentian Violet / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D053768:Metal Nanoparticles / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000032:analysis; D013059:Spectrum Analysis, Raman / Q000379:methods*; D055672:Static Electricity; D013917:Thrombin / Q000032:analysis*
chemical_list: D052158:Aptamers, Peptide; D007070:Immunoglobulin A; D012710:Serum Albumin, Bovine; D006046:Gold; D013917:Thrombin; D005840:Gentian Violet