**Abstract**

In this chapter, an impedimetric response of iron (III) porphyrin (Fe(III)TMPP) functionalized on gold transducer towards the detection of three phenolic compounds entitled bisphenol A (BPA), 2,2<sup>0</sup> -biphenol and catechol has been studied. The bisphenol A that has revealed the best affinity with Fe(III)TMPP membrane has been chosen as the target analyte. For improved sensitivity of Au/Fe(III)TMPP sensor towards BPA, a facile and efficient Au/RGO nanocarbon transducer based on reduced graphene oxide (RGO) has been prepared and used to support Fe(III)TMPP membrane. The obtained Au/RGO/Fe(III)TMPP structure was characterized by UV–visible (UV–vis) and electrochemical impedance spectroscopy (EIS) measurements, then applied as electrochemical platform for BPA detection. It has been discovered that the Au/RGO nanocarbon transducer has an amplified electron transfer kinetic compared to unmodified Au transducer. The Au/RGO/Fe(III)TMPP structure has showed a better affinity towards BPA with a doubled sensitivity compared to that obtained with Au/Fe(III)TMPP electrode. We demonstrated that the Au/RGO nanocarbon transducer not only enhances the electron transfer ability but also serves as a good template for the attachment of Fe(III)TMPP through *π*- *π* interaction. This study reveals new high-potential of nanocarbon transducer based on RGO for the conception of electrochemical sensors with high sensitivity and short response time.

**Keywords:** iron (III) porphyrin, reduced graphene oxide, impedimetric sensor, nanocarbon transducer, bisphenol A
