Hybridization chain reaction-based Label-free colorimetric sensor for detection of cancer marker p53 gene

Abstract

Abstract The p53 gene, a crucial tumor suppressor gene, plays a significant role in cancer prevention, diagnosis, and prognostic assessment. Accurate and sensitive detection of the p53 gene is essential for early cancer screening and diagnosis. To address the need for a sensitive, cost-effective, and scalable method for p53 gene detection, a label-free colorimetric sensor based on the hybridization chain reaction (HCR) in conjunction with gold nanoparticles (AuNPs) were developed. In the absence of the p53 gene, the hairpin DNA probes prevent the aggregation of AuNPs induced by salt through the interaction of single-stranded DNA at the sticky end with the AuNPs. Upon the introduction of the p53 gene, the hybridization chain reaction was initiated. The H1 and H2 hairpin probes were depleted and the AuNPs became exposed, leading to their aggregation when salt was added. This aggregation caused a color change in the solution from red to blue-violet. The concentration of p53 can be detected by monitoring the color change of the solution. The hairpin probes H1 and H2 for hybridization chain reaction were designed with P53 sequence as initiator. The reaction process of HCR was verified by fluorescence spectra and gel electrophoresis. The results showed that the naked eye visual detection limit of the sensor was 2nM, the quantitative detection limit by UV-visible spectrophotometer was 0.2nM, and the linear detection range was 0.2nM to 200nM with obvious specificity. Notably, this was the first time that an enzyme-free and label-free colorimetric method was introduced for this gene, greatly reducing the difficulty and cost of the experiment. which is very conducive to market application, and provides a new idea for the early large-scale screening of cancer genes.