An aptamer-based assay for thrombin via structure switch based on gold nanoparticles and magnetic nanoparticles

• Published in: Talanta (Oxford) 2010-03, Vol.80 (5), p.1868-1872
• Main Authors: Zheng, Jing, Cheng, Gui-Fang, He, Pin-Gang, Fang, Yu-Zhi
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Aptamer; Aptamers, Nucleotide - chemistry; Aptamers, Nucleotide - metabolism; Biosensing Techniques - economics; Biosensing Techniques - methods; Chemistry; Electrochemical methods; Exact sciences and technology; Gold - chemistry; Gold nanoparticle; Magnetic nanoparticle; Magnetics; Microscopy, Electron, Scanning; Nanoparticles - chemistry; Sensitivity and Specificity; Temperature; Thrombin; Thrombin - analysis; Thrombin - metabolism
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2009.10.036

An aptamer-based assay for thrombin with high specificity and sensitivity was presented. In the protocol, the aptamer for thrombin was immobilized on magnetic nanoparticle, and its complementary oligonucleotide was labeled with gold nanoparticles, then the aptamer was hybridized with the complementary oligonucleotide to form the duplex structure as a probe, this probe could be used for the specific recognition for thrombin. In the presence of thrombin, the aptamer prefer to form the G-quarter structure with thrombin, resulting in the dissociation of the duplex of the probe and the release of the gold labeled oligonucleotide. Upon this, we were able to detect thrombin through the detection of the electrochemical signal of gold nanoparticles. The strategy combines with the high specificity of aptamer and the excellent characteristics of nanoparticles. This assay is simple, rapid, sensitive and highly specific, it does not require labeling of thrombin, and it could be applied to detect thrombin in complex real sample. The method shows great potential in other protein analysis and in disease diagnosis.