A reusable electrochemiluminescence biosensor controlled by a nanochannel gating system for T-2 toxin detection

Abstract

A reusable electrochemiluminescence (ECL) biosensor based on the switchable gating property of nanochannels has been successfully developed and applied in the detection of T-2 toxin. The sensing interface was achieved by modifying nanoporous anodic aluminum oxide membrane with gold nanoparticles and T-2 aptamers, which has a switchable gating property triggered by the target. Once triggered by the target, the gating system could be switched from the "OFF" state to the "ON" state allowing diffusion of ascorbic acid (AA) and H₂O₂. Due to the consumption of reactive oxygen species by AA, ECL signals of luminol/Au NPs was significantly inhibited. Through the treatment of heating and washing, captured T-2 toxin can be fully released and the gating system can be switched to the “OFF” state and applied in the following detection. Due to the spatial separation, reactivation of the sensing interface by repeated heating and washing will not affect the ECL emitters after repeated tests. This biosensor was applied in the analysis of actual samples. There’s a good linear relationship between ECL intensity and the logarithm value of the concentration in the range of 10 pg mL⁻¹ to 100 μg mL⁻¹ with a limit of detection of 3.2 pg mL⁻¹.