Fabrication of potentiometric sensor based on new and high-performance nanocomposite of molecular imprinting for the determination of tramadol

In the present research, a new, sensitive and high-performance potentiometric sensor for the determination of tramadol in various real samples were designed and fabricated. A novel nano-composite layer was suggested for the construction of this sensor. The proposed nano-sensing layer composed of a new carbon paste matrix including; graphite powder, a new synthesized tramadol imprinted polymer nanoparticles "as an essential sensing element", graphene nanosheets and an ionic liquid of 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide as the conductive pasting binder. Under the optimized conditions, the new suggested sensor presented the detection limit of 8.90×10−9 mol L−1 and the linear range of 3.50×10−8 to 1.00×10−2 mol L−1 with a Nernstian slope of 59.73±0.20 mV decade−1. Also, this sensor displays an excellent selectivity for tramadol with respect to number of other same species. It has a fast response with response time of about 6 s, and can be used for at least 3.5 months without any considerable divergence in the potentials. Finally, the presented sensor was successfully used for the trace level determination of tramadol in pharmaceutical and biological samples.