A fluorometric aptamer based assay for prostate specific antigen based on enzyme-assisted target recycling

Abstract Prostate specific antigen (PSA) is considered to be a well-established biomarker for prostate cancer, and the importance of PSA assay is increasing in order to improve the diagnosis and prognosis of prostate cancer. However, there are still some weaknesses with current methods of PSA detection including high-cost, heavy analyzer and complexed procedure, restricting the application of PSA assay in prevention of diseases. In this paper, we designed a novel fluorometric aptasensor for PSA assay. Inspired by the concept of enzyme-assisted target recycling (EATR), this novel aptasensor shows an excellent signal responsiveness by the exclusive recognition between aptamer and PSA, together with significant signal amplification through EATR. After systematic optimization, this method shows an excellent detective performance with a sensitive LOD at 0.043 pg mL−1(S/N = 3) and wide linear range of 0.05–150 pg mL−1. To verify the potential of practical application, a set of biomarkers that often co-exist in PSA samples and diluted human serum samples are used for selectivity and practical performances evaluation, and it turns out that this aptasensor exhibits selectivity and potential for clinical application. Specially, this method is easily performed under isothermal environment and needless of complexed preparation, making it more possible for wide application. In view of the superiority, a promising perspective can be provided by this method for practical PSA assay, further promoting the development of precise medicine and oncology.