Dual-site PGM-based point-of-care detection of EGFR exon 19 deletion with an endogenous internal control

Rapid and reliable detection of EGFR exon 19 deletion (19del) is important for precision treatment of non-small cell lung cancer, yet current genotyping methods remain poorly suited for point-of-care testing (POCT). This limitation is particularly significant in signal-off assays, where reaction failure can be misinterpreted as a true negative result. Here, we present a dual-site personal glucose meter (PGM)-readout platform for minimal-instrumentation analysis of EGFR 19del. In this system, target-dependent flap endonuclease 1 (FEN1) cleavage generates adenosine monophosphate (AMP), which triggers a glucose-consuming kinase cascade and enables direct quantitative readout using a commercial PGM without optical instrumentation or nucleic acid amplification. To improve interpretability, the platform incorporates an endogenous internal control through a dual-site design consisting of a mutation-discriminating detection site and a conserved control site, thereby enabling reliable interpretation of signal-off readouts while confirming sample adequacy. The platform achieved sensitive detection with a limit of detection of approximately 27 pM and discriminated mutation fractions down to ∼0.44% in wild-type/mutant mixtures. Its feasibility was further demonstrated using cell-derived genomic DNA and serum-containing samples. These results indicate that the proposed platform provides an accessible and practical strategy for decentralized EGFR 19del testing.