A dual-amplification system for colorimetric DNA detection based on the assembly of biomolecules

Abstract

A dual-amplification system is reported to apply in DNA sensing via the assembly of DNA and protein. In this process, the biotinylatedcapature DNA bounded with streptavidin (SA) through the biotin-streptavidin reaction, and then the assembly of DNA and protein was triggered by the linker DNA after the target hybridized with biotinylatedcapature DNA. Sequentially, the 3,3',5,5'-tetramethylbenzidine (TMB) was oxidized by H2O2 under the catalysis of horseradish peroxidase. Based on the variation of the color and the UV–vis absorbance intensities, qualitative and quantitative DNA analyses were realized. This proposed method could detect the target DNA as low as 1.75pmol/L and discriminate perfectly matched target DNA from the mismatch DNA. What’s more, it can be expanded to detect other molecules with a reasonable design of the corresponding DNA sequences.