A Universal and Sensitive Sensing Platform for Biomolecular Detection based on the Hybridization Chain Reaction Amplification and Gold Nanoparticles Colorimetry

Abstract A universal and sensitive target analysis strategy was constructed by combining the hybridization chain reaction (HCR) and gold nanoparticles (AuNPs) colorimetry. Based on this strategy, we realized the detection of target DNA and thrombin. For the detection of target DNA, the hairpin chain H1 (H1) and the hairpin chain H2 (H2) could trigger HCR in the presence of target DNA. Subsequently, the HCR products could hybridize with DNA-AuNPs and make the aggregation of AuNPs, resulting in a dynamically change in the absorbance at the wavelength of 522 nm. Furthermore, the detection limit of target DNA was 4.47 pM. For the detection of thrombin, the primer could be designed according to the aptamer. The designed primer bound to the aptamer to prevent HCR in the absence of thrombin. Once upon the addition of thrombin, the thrombin preferentially bound to the aptamer, thus the primer could be released to trigger HCR. Afterwards, the HCR products hybridized with DNA-AuNPs, thus realizing the detection of thrombin. Finally, the detection limit of thrombin was 1.26 pM. Consequently, by designing the sequence of primer, the strategy exhibited good universality for the detection of different targets, which had great potential in biosensing.