Allosteric aptasensor-initiated target cycling and transcription amplification of light-up RNA aptamer for sensitive detection of protein

• Published in: Sensors and actuators. B, Chemical Vol. 371; p. 132526
• Main Authors: Song, Danxia, Yuan, Deyu, Tan, Xuemei, Li, Ling, He, Huan, Zhao, Liang, Yang, Gang, Pan, Sirui, Dai, Hongyuan, Song, Xu, Zhao, Yongyun
• Format: Journal Article
• Language: English
• Published: Switzerland Elsevier B.V 15.11.2022; Elsevier Science Ltd
• Subjects: Allosteric aptasensor; Amplification; Biomarkers; Cycles; Diagnosis; Light-up RNA aptamer; Protein detection; Proteins; Severe acute respiratory syndrome coronavirus 2; Target cycling signal amplification; Transcription amplification; Target cycling signal amplification; Allosteric aptasensor; Protein detection; Light-up RNA aptamer; Transcription amplification
• ISSN: 0925-4005; 1873-3077; 0925-4005
• DOI: 10.1016/j.snb.2022.132526

The early detection of biomarker proteins in clinical samples is of great significance for the diagnosis of diseases. However, it is still a challenge to detect low-concentration protein. Herein, a label-free aptamer-based amplification assay, termed the ATC-TA system, that allows fluorescence detection of very low numbers of protein without time-consuming washing steps and pre-treatment was developed. The target induces a conformational change in the allosteric aptasensor, triggers the target cycling and transcription amplification, and ultimately converts the input of the target protein into the output of the light-up aptamer (R-Pepper). It exhibits ultrahigh sensitivity with a detection limit of 5.62 fM at 37 ℃ and the accuracy is comparable to conventional ELISA. ATC-TA has potential application for the detection of endogenous PDGF-BB in serum samples to distinguish tumor mice from healthy mice at an early stage. It also successfully detects exogenous SARS-CoV-2 spike proteins in human serum. Therefore, this high-sensitive, universality, easy-to-operate and cost-effective biosensing platform holds great clinical application potential in early clinical diagnosis. •A novel label-free aptamer-based cascade amplification platform for low-abundance protein detection is developed.•This system is high-sensitive, universality, cost-effective and easy to operate without any washing and separation steps.•It realizes fluorescence detection, real-time detection and visual detection of proteins, providing optional analysis.•R-Pepper can tolerate the existence of more unrelated sequences, widening the application scope of the light-up aptamer.