فهرست نشریات علمی دسترسی آزاد ایران

Exosomes are promising cancer biomarkers but require sensitive, low cost detection methods. We present a label-free, paper-based electrochemical immunosensor that utilizes a ternary Hemin–mesoporous carbon foam (MCF)–multiwall carbon nanotube (MWCNT) nanocomposite as both an electrode modifier and an internal probe. Hemin-loaded MCF integrated with carboxylated MWCNTs produces a conductive, high-surface-area platform that enables direct signal generation without the need for external labels. The composite was immobilized on a carbon-ink three-electrode paper strip via anti-CD9 antibodies for exosome capture. Electrochemical characterization verified composite formation, antibody attachment, and target binding. Under optimized conditions, the sensor showed a linear response from 5 × 102 to 5 × 105 exosomes μL−1 and a limit of detection of 150 exosomes μL−1. DPV currents decreased with increasing exosome load due to the formation of an insulating protein layer, allowing quantification from ΔI. The device exhibited high selectivity, good reproducibility, and stability. Analysis of diluted human serum produced recoveries consistent with ELISA. This low-cost, disposable platform is suitable for rapid exosome analysis and adaptable to multiplexed point-of-care diagnostics.