Nowadays, considerable efforts are focused on advancing DNA detection methods, which are extremely important in clinical diagnostics, pathogen determination, gene therapy, and forensic analysis. A one-pot sensitive microplate-based chemiluminescent assay coupled with catalytic hairpin assembly (CHA) amplification for detection of a 35-mer DNA oligonucleotide was developed. To improve the assay sensitivity, a triple amplification strategy based on the application of CHA (1), streptavidin-polyperoxidase conjugate (Stp-polyHRP) (2), and an enhanced chemiluminescent reaction (3) was used. The one-pot format of the assay, where all steps of the DNA determination are performed in the same well without transfer of samples from one test tube to another, increased its precision. The proposed assay detected the target DNA in the fM range and distinguished the target DNA from related DNAs, demonstrating its high sensitivity and high selectivity. Moreover, the assay was applied successfully for the quantitative determination of the target in spiked samples of human plasma. A microplate format of the assay was convenient for the analysis of a large number of samples. This study provides a prospective tool for DNA detection. Graphical abstract.
Keywords: Catalytic hairpin assembly; DNA detection; Enhanced chemiluminescence; Isothermal amplification; Microplate-based assay; Polyperoxidase conjugate.