Biomembrane-modified field effect transistors for sensitive and quantitative detection of biological toxins and pathogens

Summary

This biosensor study develops a function-based detector for toxins and pathogen-derived samples whose molecular composition may be complex or unknown. Carbon-nanotube field-effect transistors were coated with natural red-blood-cell membrane. Because erythrocyte membranes interact with many hemolytic toxins, the biological layer captured targets without requiring a different recognition antibody for every molecular structure. Binding changed local charge near the transistor surface, generating concentration-dependent electrical signals with reported detection into the femtomolar range. A built-in calibration scheme corrected fabrication differences between sensor batches and enabled quantitative measurements. Performance was demonstrated with three distinct toxins and complex bacterial supernatants. Signals from secreted bacterial proteins also correlated linearly with actual bacterial abundance, allowing rapid concentration estimates without colony counting. The principal finding is that a natural membrane can serve simultaneously as broad recognition interface and signal-coupling layer on an electronic device. Its significance is molecularly agnostic sensing based on biological function rather than prior target identification, potentially useful for rapidly characterizing pathogenic activity. The abstract does not provide selectivity panels, response times, false-positive rates, field-sample validation, device stability, or direct comparison with established microbiological and toxin assays.