title: A simple electrochemical aptasensor for ultrasensitive protein detection using cyclic target-induced primer extension.
abstract: A simple electrochemical aptasensor was developed for ultrasensitive protein detection by combining a novel strategy of cyclic target-induced primer extension (CTIPE) with an aptamer-hairpin probe and enzyme-amplified electrochemical readout. In the presence of protein target, the immobilized aptamer-hairpin probe recognized the protein to trigger primer extension reaction by target-induced conformational transition, which released the protein from replicated DNA duplex. The released target could cyclically bind with other aptamer-hairpin probes and trigger new primer extension, leading to formation of numerous biotin-tagged DNA duplex, which significantly amplified the protein recognition event and facilitated the subsequent enzymatic signal enhancement, leading to an ultrasensitive electrochemical aptasensor. Using human vascular endothelial growth factor as a model protein, the designed aptasensor could detect protein down to 0.82 pg mL(-1) with a linear range from 1 pg mL(-1) to 1 ng mL(-1). The proposed aptasensor was amenable to quantification of protein in complex biological matrixes, and would become a simple and powerful tool for bioanalysis and clinic diagnostic application.
authors.affiliation: Key Laboratory of Laboratory Medical Diagnostics-Ministry of Education of China, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.forename: Shijia
authors.initials: S
authors.lastname: Ding
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: Tianxiao
authors.initials: T
authors.lastname: Yu
authors.forename: Yibin
authors.initials: Y
authors.lastname: Yin
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
authors.forename: Guosheng
authors.initials: G
authors.lastname: Ren
mesh_terms: D052158:Aptamers, Peptide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D004261:DNA Replication; D055664:Electrochemical Techniques; D006801:Humans; D011506:Proteins / Q000302:isolation & purification*; D042461:Vascular Endothelial Growth Factor A / Q000302:isolation & purification*
chemical_list: D052158:Aptamers, Peptide; D011506:Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A