A novel nanotechnology-based strategy using CNT-Fe3O4 for early and accurate detection of EGFR T790M mutation in NSCLC

A magnetically responsive carbon nanotube–iron oxide (CNT–Fe3O4) nanocomposite was synthesized and surface-functionalized with citric acid to introduce carboxyl groups suitable for stable bio conjugation. A mutation-specific amine-modified oligonucleotide probe targeting the EGFR T790M resistance mutation was covalently immobilized onto the activated nanocomposite using EDC/NHS coupling, forming a selective molecular biosensing platform. DNA extracted from FFPE tumor tissues of NSCLC patients was evaluated through a fluorescence-based hybridization assay integrated with magnetic separation to reduce nonspecific adsorption. T790M-positive samples showed clearly higher measured DNA concentration values after hybridization (5.9–7.4 ng/µL; mean = 6.7 ± 0.6 ng/µL), whereas negative and control samples remained low (1.7–2.3 ng/µL), confirming the analytical specificity and reproducibility of the developed system.This platform offers a rapid, cost-effective, and portable approach for mutation detection without requiring complex instrumentation. The CNT–Fe3O4–probe nanoplatform demonstrates promising potential for future translation into liquid biopsy applications and personalized therapeutic monitoring in NSCLC.