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Updated: Mar 1, 2026
Aptamer-Based Target Detection Facilitated by a 3-Stage G-Quadruplex Isothermal Exponential Amplification Reaction
Published on: October 6, 2022
Ultrasensitive detection of nucleic acids and proteins using quartz crystal microbalance and surface plasmon
Wenbo Sun1, Weiling Song2, Xiaoyan Guo2
1Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, College of Chemical Science and Engineering, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Shandong 266071, PR China.
Abstract:
In this study, quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) sensors were combined with template enhanced hybridization processes (TEHP), rolling circle amplification (RCA) and biocatalytic precipitation (BCP) for ultrasensitive detection of DNA and protein. The DNA complementary to the aptamer was released by the specific binding of the aptamer to the target protein and then hybridized with the capture probe and the assistant DNA to form a ternary "Y" junction structure. The initiation chain was generated by the template-enhanced hybridization process which leaded to the rolling circle amplification reaction, and a large number of repeating unit sequences were formed. Hybridized with the enzyme-labeled probes, the biocatalytic precipitation reaction was further carried out, resulting in a large amount of insoluble precipitates and amplifying the detection signal. Under the optimum conditions, detection limits as low as 43 aM for target DNA and 53 aM for lysozyme were achieved. In addition, this method also showed good selectivity and sensitivity in human serum.
