Designed electrochemical sensor based on metallocene modified conducting polymer composite for effective determination of tramadol in real samples

A novel composite for the electrochemical sensing of tramadol (Tr) was developed by the inclusion of metallocene mediator between two layers of conducting poly(3,4-ethylenedioxythiophene) (PEDOT) polymer, in presence of sodium dodecyl sulfate (SDS); (P/mediator/P…SDS). Three charge transfer mediators were evaluated: ferrocene carboxylic acid (FC1), ferrocene (FC2) and cobaltocene (CC) for Tr electrocatalytic oxidation. FC1-charge mediator showed relatively higher current response that was assisted by the electronic conduction of the polymer film. Moreover, SDS presented a great impact, resulting in the enhancement of the preconcentration/accumulation of Tr ions at the interface leading to faster electron transfer. In addition, the practical application of the proposed FC1 composite for the determination of Tr in real urine and serum samples was successfully achieved with adequate recovery results. Very low detection limits of 18.6 nM and 16 nM in the linear dynamic ranges of 7 M to 300 M and 5 M to 280 M, respectively, were obtained at the proposed sensor. Furthermore, the simultaneous determination of of Tr with common interfering species; paracetamol (PAPA), morphine (MO), dopamine (DA), ascorbic acid (AA) and uric acid (UA) proved excellent with good resolution and large potential peaks separation. The excellent characteristics of the proposed composite such as high reproducibility, good sensitivity, selectivity, anti-interference ability and good stability enhanced its application for determination of other narcotics drugs.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author