Compositing a Silver-Palladium Bimetallic Core-Shell Onto the Surface of Polyethylenimine-Modified Graphite Oxide as the Electrode Modification Material for the Electrochemical Aptasensor Detection of Procymidone

Abstract

The occurrence of procymidone (PCM) in vegetables surpassing the permissible limits has become a recurring issue in recent years, posing a grave threat to public health in recent years. Herein, an electrochemical aptasensor based on signal expanding upon strategy was developed for the sensitive detection of PCM. AgPd nanoparticles/Polyethylenimine Graphite oxide (AgPdNPs/PEI-GO) was weaned as electrode modification material to facilitate electron transport and increase the active sites on the electrode surface and provided more binding sites for complementary DNA (cDNA). Besides, Pt@Ni-Co hollow nanoboxes (Pt@Ni-CoHNBs) were utilized to be carriers for signaling tags, after hollowing ZIF-67 and growing Pt, the resulting Pt@Ni-CoHNBs has a tremendous amounts of folds occurred on the surface, enables it to carry a larger quantity of thionine (Thi), thus amplify the detectable electrochemical signal. In the presence of PCM, the binding of PCM to the signal probe would trigger a significant change in electrical signal, enabling the quantitative measurement of PCM. The aptasensor was demonstrated with excellent sensitivity and a low detection limit of 0.98 pg·mL-1, along with a wide linear range of 1 μg·mL-1 to 1 pg·mL-1. Meanwhile, the specificity, stability and reproducibility of the constructed aptasensor were proved to be satisfactory, providing a new idea for the sensitive detected PCM in agricultural products.

Keywords: procymidone, aptasensor, AgPdNPs/PEI-GO, Pt@Ni-CoHNBs