Highly Sensitive Detection of Protein with Aptamer-Based Target-Triggering Two-Stage Amplification

• Published in: Analytical chemistry (Washington) Vol. 84; no. 3; pp. 1623 - 1629
• Main Authors: Zhang, Zhen-zhu, Zhang, Chun-yang
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 07.02.2012
• Subjects: Analytical chemistry; Aptamers, Nucleotide - chemistry; Binding sites; Biomarkers; Biomedical research; Chemistry; DNA Probes - chemistry; Exact sciences and technology; Fluorescent Dyes - chemistry; Nucleic Acid Amplification Techniques; Peptides; Proteins; Proto-Oncogene Proteins c-sis - analysis; Spectrometric and optical methods; Spectrometry, Fluorescence; Isothermal condition; Chemical analysis; Antibody; Use; Fluorescence; Biological marker; Time; Method; Probe; Conformational changes; Protein; Fluorescence spectrometry; Gene amplification; Target; Sensitivity; Signal; Specificity; Platelet; DNA; Detection limit; Diagnosis; Detection
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac2029002

Highly sensitive detection of proteins is essential to biomedical research as well as clinical diagnosis. However, so far most detection methods rely on antibody-based assays and are usually laborious and time-consuming with poor sensitivity. Here, we develop a simple and sensitive method for the detection of a biomarker protein, platelet-derived growth factor BB (PDGF-BB), based on aptamer-based target-triggering two-stage amplification. With the involvement of an aptamer-based probe and an exponential amplification reaction (EXPAR) template, our method combines strand displacement amplification (SDA) and EXPAR, transforming the probe conformational change induced by target binding into two-stage amplification and distinct fluorescence signal. This detection method exhibits excellent specificity and high sensitivity with a detection limit of 9.04 × 10–13 M and a detection range of more than 5 orders of magnitude, which is comparable with or even superior to most currently used approaches for PDGF-BB detection. Moreover, this detection method has significant advantages of isothermal conditions required, simple and rapid without multiple separation and washing steps, low-cost without the need of any labeled DNA probes. Furthermore, this method might be extended to sensitive detection of a variety of biomolecules whose aptamers undergo similar conformational changes.