Development of Reusable Electrochemiluminescence Sensing Microchip for Detection of Vomitoxin

Abstract

In this work, a reusable DNA sensing microchip was developed for detection of vomitoxin in sorghum using Cd-based core-shell CdSe@CdS quantum dots (QDs) as promising electrochemiluminescence (ECL) emitter. The size-adjustable aqueous phase CdSe@CdS QDs were prepared through homogeneous method, exhibiting strong cathodic ECL emission with a central wavelength of 520 nm in S2O82- coreactant. While gold nanoparticles-modified iron cobalt cyanide hydrate (Fe-Co-Au) as an accelerator was introduced to amplify the signal through reversible redox property. Quantitative conversion of vomitoxin (deoxynivalenol, DON) concentration to visualize ECL signal is achieved by unlocking an electron transfer quenching system between the emitter and ferrocene (Fc), which are modified on the aptamer or its complement sequence, respectively. The introduction of the DON target can trigger the unbinding of double strands DNA (dsDNA) and the release of the complement strand, thus the signal can be generated. This approach offers a feasible method for the detection of DON within the range of 1 ng/mL to 200 ng/mL.

Keywords: electrochemiluminescence, biosensing microchip, CdSe@CdS QDs, vomitoxin