Impedimetric ultrasensitive detection of chloramphenicol based on aptamer MIP using a glassy carbon electrode modified by 3-ampy-RGO and silver nanoparticle.

In this research work, a biosensor with a dual recognition system was fabricated and founded on a combination of aptasensing and the molecular imprinting union of the chloramphenicol (CAP) selective detection. CAP, is an antibiotic, was applied in veterinary and human in order to treat gram-positive and gram-negative infections. It is worth mentioning that CAP residue brings about earnest side effects on human health. According to this, in this sensing system, 3-aminomethyl pyridine functionalized graphene oxide (GO) (3-ampy-RGO) has been coated on the surface of GCE. Afterwards, the silver nanoparticle (AgNPs) was coated on the 3-ampy-RGO/GCE and, then, the CAP complex-amino-aptamer (NH2-Apt[CAP]) was attached to the AgNP/3-ampy-RGO/GCE using a kind of bonding formation of Ag-N. In this sense, it is worth noting that the resorcinol electropolymerization around the complex of aptamer/CAP would confine the complex and, then, retain the aptamer. Following the CAP removal, the MIP cavity, as it was supposed, synergistically acted with that of the embedded aptamer in order to construct a nanohybrid receptor. Interestingly, the double exact property of the molecular imprinting polymers and aptamers led to the superb sensing properties. In the mentioned system it was illustrated that the linear range was from 1.0 pM to 1.0 nM with the detection limit of 0.3 pM; consequently, as observed, it was better than or as good as other similar assays. Moreover, the mentioned system whose activity was observed in the various interferences presence showed great selectivity in detected the CAP. Finally, the designed sensor exhibited outstanding results when applied to detect CAP in milk samples.