Competitive bridge probes for electrochemical analysis of diverse DNA variants in nanoenzyme-enhanced assay

The analysis of single nucleotide polymorphism (SNP) is an effective approach for evaluating tumor initiation and progression. However, the high homology between wild-type and mutant sequences poses challenges in distinguishing between them. Additionally, many cancer-related genes harbor numerous distinct mutations, leading to a lack of efficient and practical methods for analyzing SNPs markers. In this study, we report an electrochemical method for the specific detection of SNPs using competitive bridge probes (CBPs). Through rational design, the CBPs can detect multiple mutant alleles from the same region of the gene. All SNPs-induced probe recognition and bridge-hybridization introduce nanozyme sensitizing factors into the electrochemical sensing system, which catalyze the decomposition of hydrogen peroxide, generating a significant electrochemical signal. As a proof of concept, the proposed biosensor has demonstrated to quantitatively detect various target KRAS variants. Given the high sensitivity, accessibility and versatility of the detection results, we believe the electrochemical biosensing platform we designed holds potential for future applications in cancer clinical diagnosis.