title: Electrochemical aptamer sensor for thrombin detection based on Au nanoneedle and enzymatic ascorbic acid oxidization.
abstract: In this article, we describe an aptamer-based sandwich-type electrochemical sensor for the detection of human alpha-thrombin. Au nanoneedles were synthesized in the hole of the naked polycarbonate (PC) template using electrodepositing strategy. The thiolated thrombin aptamer I was immobilized as the capture probe on the gold nanoneedles through Au-S bond. After the thrombin was captured, the biotinylated aptamer II, used as the detection probe, was bound to thrombin. Then, the streptavidin-conjugated alkaline phosphatase (SA-ALP) was linked to the biotinylated aptamer II and catalyze hydrolyzation reaction of ascorbic acid 2-phosphate to produce ascorbic acid. Differential pulse voltammetry was used to detect the oxidizing current of ascorbic acid, which is proportional to the concentration of thrombin bound on the electrode surface ranging from 0.24 nM to 150 nM with a detection limit of 0.1 nM at 3 sigma. This assay is rapid, simple, sensitive and highly specific. It could be applied to detect thrombin in complex real sample.
authors: College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650092, China.
authors: Feng
authors: F
authors: Xu
authors: Mei
authors: M
authors: Hua
authors: Lei
authors: L
authors: Luo
authors: Huali
authors: H
authors: Du
authors: Yunhui
authors: Y
authors: Yang
mesh_terms: D000469:Alkaline Phosphatase / Q000737:chemistry*; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001205:Ascorbic Acid / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000295:instrumentation; D009339:Needles; D010084:Oxidation-Reduction; D013917:Thrombin / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D006046:Gold; D000469:Alkaline Phosphatase; D013917:Thrombin; D001205:Ascorbic Acid