title: Label-free electrochemical aptasensor for adenosine detection based on cascade signal amplification strategy.
abstract: In this work, a simple and highly sensitive label-free electrochemical aptasensor for adenosine detection was developed based on target-aptamer binding triggered nicking endonuclease-assisted strand-replacement DNA polymerization and rolling circle amplification (RCA) strategy. The magnetic beads (MB) probe, which was attached the aptamer of adenosine and mDNA, was firstly fabricated. In the presence of adenosine, mDNA was released from MB upon recognition of the aptamer to target adenosine. The released mDNA as the primer activated autonomous DNA polymerization/nicking process and accompanied by the continuous release of replicated DNA fragments. Subsequently, numerous released DNA fragments were captured on the working electrode, and then as initiators to trigger the downstream RCA process leading to the formation of a long ssDNA concatemer for loading large amounts of Ru(NH3)63+. Therefore, a conspicuously amplified electrochemical signal through the developed dual-amplification strategy could be achieved. This method exhibited a high sensitivity toward adenosine with a detection limit of 0.032nM. Also, it exhibited high selectivity to different nucleoside families and good reproducibility. This design opens new horizons for integrating different disciplines, presenting a versatile tool for ultrasensitive detecting organic small molecules in medical research and clinical diagnosis.
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, Shandong 266042, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Shen
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, Shandong 266042, China.
authors.forename: Hongyang
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, Shandong 266042, China. Electronic address: lichunxiang76@126.com.
authors.forename: Chunxiang
authors.initials: C
authors.lastname: Li
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, Shandong 266042, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, Shandong 266042, China.
authors.forename: Xijuan
authors.initials: X
authors.lastname: Yu
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, Shandong 266042, China. Electronic address: xiliangluo@qust.edu.cn.
authors.forename: Xiliang
authors.initials: X
authors.lastname: Luo
mesh_terms: D000241:Adenosine / Q000737:chemistry / Q000302:isolation & purification*; D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques; D006801:Humans; D057230:Limit of Detection; D021141:Nucleic Acid Amplification Techniques
chemical_list: D052157:Aptamers, Nucleotide; D004247:DNA; D000241:Adenosine
keywords: Adenosine detection; Aptamer; Electrochemical sensor; RCA; Strand-replacement DNA polymerization