A Dual Amplification Photoelectrochemical Platform for KRAS Mutation Detection

Objective

Cancer causes ~10 million deaths annually and a projected $25.2 trillion economic burden by 2050. Nearly half of cases are diagnosed late, underscoring the need for rapid and sensitive diagnostic tools. The KRAS oncogene is a major driver of colorectal, pancreatic, and lung cancers and serves as a critical biomarker for early detection, prognosis, treatment selection, and recurrence monitoring. With approved KRAS inhibitors and >85 investigational agents, the demand for accurate mutation testing is rising. Current circulating tumor DNA assays rely on polymerase chain reaction (PCR) and next-generation sequencing (NGS), which achieve low mutant allele fraction (MAF) thresholds but require thermal cycling, costly instruments, and central laboratories. Optical and electrochemical alternatives simplify hardware but remain limited to picomolar detection and often lack selectivity in high wild-type backgrounds. To address these challenges, I introduce PEAKRAS, a highly sensitive, dual-amplification photoelectrochemical (PEC) assay for KRAS mutation detection. The platform physically integrates mismatch hairpin recycling with singlet oxygen–mediated PEC redox cycling, enabling two layers of amplification without thermal cycling or electrode modification. This design targets a limit of detection of 0.1–10 fM while enabling reliable discrimination of mutant alleles below 1% MAF in plasma. By combining molecular selectivity encoded in mismatch hairpin kinetics with a simple, portable PEC transduction scheme, PEAKRAS overcomes major barriers to point-of-care mutation testing.