Integration of Surface‐enhanced Raman Spectroscopy with PCR for Monitoring Single Copy of KRAS G12D Mutation

Identification and monitoring cancer‐related genetic mutation become a powerful tool for targeted therapy in recent decades and KRAS is one of the most frequently mutated oncogenes in many types of cancers. Polymerase chain reaction (PCR) is one of the most powerful diagnostic tools and it is widely used for monitoring infectious diseases and tumor‐related mutations. However, there are still limitations for monitoring rare mutations in complex biological samples and also for monitoring various mutations in a multiplexed manner from a single set assay. In this study, we present an integration of surface‐enhanced Raman scattering (SERS) with PCR that can be used for monitoring KRAS G12D mutation and also can distinguish from similar mutations such as KRAS G13D, G12S, and G12V. With this approach, various KRAS mutations can be detected from a single set of experiment without complex procedures or microdevices. A SERS‐integrated PCR has been developed, without complex extraction procedures or devices. Raman probes were cleaved by target‐specific PCR. The cleaved‐probes interacted with capture sequence‐conjugated silver‐coated gold nanostars (Ag@AuNS) increasing SERS intensity. Only a blocking DNA sequence was required to prevent uncleaved‐probes from interacting with the capture sequence‐conjugated Ag@AuNS. With this SERS‐PCR, KRAS G12D mutation was specifically identified in a single gDNA manner.