Label-free and specific detection of active Botulinum neurotoxin in 0.5 L drops with the meta-nano-channel field-effect biosensor

Botulinum neurotoxins (BoNT) are the most poisonous and lethal substances known to humans, and as such there is a great need for fast, easy-to-use, and early BoNT detection technologies which are not available today. A biosensor based on field-effect transistor (FET) is a highly pursued sensing platform due to the inherent low-noise and amplification, low-cost, and the ultimate potential for the sensing of multiple analytes from an ultra-small sample volume. In the current study we employ the novel Meta-Nano-Channel (MNC) FET biosensor for specific and label-free sensing of BoNT. The MNC biosensor is a multi-channel device which provides the means to optimize the coupling between the biological interactions and the readout sensing current, by applying a tight control over both the electrodynamics of the sensing current and the electrostatics of the biological interactions. Importantly, the MNC FET biosensor presents excellent stability, repeatability and robustness in wet conditions. Finally, the multi-channel approach of the MNC biosensor allows for tunable sensing performance in terms of limit-of-detection, sensitivity and dynamic range.