High sensitive, colorimetric, isothermal nucleic acids amplification: A versatile platform for protein biosensors

Colorimetric, in situ, isothermal rolling circle amplification (RCA)-based biosensor was developed as a novel, versatile nucleic acid-based amplification machine for platelet-derived growth factor (PDGF) detection. This antibody-free biosensor utilized nucleic acids immobilized on the plate and DNA aptamers to capture the target protein. As compared to the conventional fluorescence measurement [1], the reported colorimetic method can facilitate the development of RCA biosensors in a high sensitive, cost-less optoelectronic detection system. Our data indicates that the colorimetric RCA assay was able to detect PDGF 0.32 nM and showed a good linear correlation between PDGF concentration and absorbance with correlation coefficient of 0.99.