Fabrication of an electrochemical biodevice for ractopamine detection under a strategy of a double recognition of the aptamer/molecular imprinting polymer

The importance of RAC tracking in human biofluids has boosted many demands for designing an ultrasensitive tool to determine the trace value of the RAC from clinical, judicial, and forensic centers. In this study, an electrochemical biodevice has developed for the highly selective detection of this illegal feed additive under a double recognition strategy of the aptamer (Apt) and molecular imprinting polymer (MIP) on a glassy carbon electrode (GCE). The sensing relies on this fact that both the MIP and Apt act synergistically to trap the RAC molecules. The sensing surface fabrication steps have been monitored by some electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV(. The charge transfer resistance (Rct) value of the redox probe as a representative of the biodevice response has increased linearly with the RAC concentration increasing in a dynamic range of 1 fM to 1.90 µM. The detection limit (LOD) value has been estimated to be 330 aM, lower than all of the reported methods in the RAC sensing. Furthermore, the practical feasibility of biodevice has been evaluated in some human blood serum and urine samples. This strategy offers some useful advantages in reliable detection of the RAC, which may help in the routine analysis, as mandated by regulatory agencies.