Ultrasensitive electrochemiluminescence aptasensor based on AuNPs@MWCNTs and Au@AgNPs for detection of profenofos residues

An ultrasensitive aptasensor based on luminol-hydrogen peroxide (H2O2) electrochemiluminescence (ECL) system was proposed for determination of profenofos. AuNPs decorated with MWCNTs (AuNPs@MWCNTs) were used to provide a favorable microenvironment for luminol loading and improve the ECL signal due to their good biological activity, excellent electrical conductivity and high specific surface area. Gold and silver core-shell nanoparticles (Au@AgNPs) could act as effective catalyzer to accelerate H2O2 decomposition to produce various intermediate reactive oxygen species for signal amplification and thus increased the ECL signal again. Under optimal conditions, the proposed ECL aptasensor obtained an extremely low detection limit of 5.32 fg/mL (S/N = 3) with a good detection range from 100 fg/mL to 1 mu g/mL. Moreover, the proposed aptasensor had excellent specificity, outstanding repeatability and favorable stability. Finally, the proposed ECL aptasensor was used for the detection of profenofos in real samples and the recoveries ranged from 94% to 102%. This strategy could provide a good reference for developing effective aptasensors for detection of other small molecules and toxins.

Automated summary

The ultrasensitive aptasensor based on luminol-hydrogen peroxide (H2O2) electrochemiluminescence (ECL) system showed excellent detection performance for profenofos, with AuNPs@MWCNTs enhancing luminol loading and Au@AgNPs catalyzing H2O2 decomposition for signal amplification. The sensor achieved a detection limit of 5.32 fg/mL and had good specificity, repeatability, and stability.