AUTHOR=Mei ChenYang , Zhang Yuanyuan , Pan Luting , Dong Bin , Chen Xingwei , Gao Qingyi , Xu Hang , Xu Wenjin , Fang Hui , Liu Siyu , McAlinden Colm , Paschalis Eleftherios I. , Wang Qinmei , Yang Mei , Huang Jinhai , Yu A-Yong TITLE=A One-Step Electrochemical Aptasensor Based on Signal Amplification of Metallo Nanoenzyme Particles for Vascular Endothelial Growth Factor JOURNAL=Frontiers in Bioengineering and Biotechnology VOLUME=10 YEAR=2022 URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2022.850412 DOI=10.3389/fbioe.2022.850412 ISSN=2296-4185 ABSTRACT=

In this study, a one-step electrochemical aptasensor was developed to detect the biomarker vascular endothelial growth factor (VEGF), an important protein in the pathogenesis of many retinal diseases, including age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, and retinal vein occlusion. The aptamer has a good affinity and can rapidly identify and capture VEGF based on its unique structure. We designed a VEGF aptasensor based on the aptamer recognition and complex metallo nanoenzyme particles as an electron exchange center and bridge between capture DNA and electrode. The aptamers maintained the hairpin structure to avoid nonspecific surface adsorption and expose the capture sequence outwards when the target was inexistent. Conversely, the aptamers opened the hairpin structure to release space to accomplish binding between VEGF and DNA, resulting in increased impedance. The performance of the electrochemical aptasensor is detected by electrochemical impedance spectroscopy (EIS). The limit of detection by EIS was as low as 8.2 pg ml−1, and the linear range was 10 pg ml−1–1 μg ml−1. The electrochemical aptasensor also showed high specificity and reproducibility.