label-free impedimetric aptasensor for methamphetamine detection based on ceria nanocomposite

Abstract: methamphetamine (meth), a potent central nervous system stimulant, is the second most widely abused drug in the world [1]. based on its chemical structure, it can be an electroactive species. however, its oxidation on the electrode surfaces is not facile. in this work, a novel aptasensor for methamphetamine (meth) detection is introduced. the structure of the meth, cerium oxide (called nanoceria; ceo2 nps) decorated on reduced graphene oxide (rgo) [2,3] was used as glassy carbon electrode modifier to study the redox behavior of meth. the aptamer selectivity and sensitivity has been enhanced by using the carbon nanomaterial. a suitable amount of ceo2 and aptamer on rgo showed a synergistic electrocatalytic effect for optimizing the meth signal. electrochemical impedance spectroscopy using [fe(cn)6]−3/−4 redox probe was used as detection technique. the obtained system also exhibits a high outstanding repeatability and selectivity and different experimental parameters were optimized to achieve the maximum response. under the optimized experimental conditions, the lowest linear dynamic range for the proposed aptasensor were obtained 0.5 nm to 250 nm. in addition, the obtained results revealed that limits of detection (lod) of the label-free impedimetric detection of meth was about 0.16 nm. the designed aptasensor exhibits an excellent repeatability and selectivity, and was effectively used to determine meth in spiked urine sample. at last, to be concluded that , wide linear range, low detection, high stability, simplicity, low cost, good reproducibility, compatibility with microfabrication, high sensitivity,large active surface, and fast response were obtained, showed proposed modified electrode can be potentially applied for the addictive drugs determination.