Sensitive colorimetric detection of protein by gold nanoparticles and rolling circle amplification.

摘要: An ultrasensitive method for the detection of protein is critically important in fundamental research and practical applications due to low abundance disease markers body fluids or tissues. To detect trace levels with high sensitivity specificity, a sensitive colorimetric biosensor assay was developed using gold nanoparticles (AuNPs) rolling circle amplification (RCA). After binding biotinylated primer/circular template streptavidin-conjugated sandwich ELISA immunocomplex, primer isothermally extended generate single-stranded DNA (ssDNA). Sequentially, padlock added hybridized RCA products. The aggregation additional AuNPs supernatant containing surplus certain concentration salt could then be observed. established sensor allowed specific α-fetoprotein (AFP) limit 33.45 pg mL−1. It also demonstrated that this distinguish 500 mL−1 AFP naked eye. In addition, applied complex sample analysis further used as universal any virus determination by changing corresponding antibodies.