Resonance energy transfer from CdTe quantum dots to gold nanorods using MWCNTs/rGO nanoribbons as efficient signal amplifier for fabricating visible-light-driven “on-off-on” photoelectrochemical acetamiprid aptasensor

Abstract

To develop novel resonance energy transfer (RET) system can provide opportunities for the goal of sensitive and inexpensive detection of aptamer-related targets such as DNA and microRNA, protein, and small-molecule. In this work, a novel RET system from CdTe quantum dots (QDs) to Au nanorods (Au NRs) was fabricated, by employing MWCNTs/reduced graphene oxide nanoribbons (MWCNTs/rGONRs) as the photoelectrochemical (PEC) signal amplifier and ideal support for QDs anchored. The photocurrent signal of CdTe QDs was amplified for ∼3.3-fold due to the sensitization effect of MWCNTs/rGONRs, and the proposed CdTe-MWCNTs/rGONRs exhibited the typical fluorescence emission at 713nm, which showed good spectral overlap with the UV–vis absorption spectrum of Au NRs. Furthermore, a visible-light-driven “on-off-on” PEC sensing strategy for sensitive and selective determination of acetamiprid was designed. Under optimal conditions, the resulting PEC aptasensor was found to be linearly proportional to the logarithm of target acetamiprid concentration in the range from 0.5pM to 10μM with a detection limit of 0.2pM. Moreover, the proposed sensor displayed high selectivity and good reproducibility, and has been successfully applied in the direct detection of acetamiprid in real food samples. This method could resist environmental interfering agents and be extended for sensitive and reliable detection of a wide range of analytes in complex samples.