Design and development of electrochemical sensors and biosensors for monitoring of hormones and their metabolites

The primary focus of my PhD research was the development, characterization, and application of nanostructured sensors and biosensors based on electrochemical transduction for monitoring hormones and their metabolites. In this context, the objective of my work was to design and optimize electrochemical sensors and biosensors, improving their analytical performance by exploring various immobilization techniques and different nanomaterials. My research concentrated on the assembly, analytical characterization, and practical applications of the sensors, as outlined here. I conducted several research studies, published in the endocrinology field, including: a tyrosinase based biosensor utilizing chitosan nanoparticles for the detection of total catecholamines in human urine samples; a simple and sensitive sensor developed using a graphite screen-printed electrode functionalized via a two-step procedure: (i) deposition of gold nanoparticles, and (ii) electro-polymerization of methylene blue was designed for 17b-estradiol detection; the development of a voltammetric biosensor for the stereoselective discrimination of myo-inositol and D-chiro-inositol based on bovine serum albumin adsorption onto a multi-walled carbon nanotube graphite screen-printed electrode [181]; and a comprehensive review providing a critical comparison of different nanoparticle-based electrochemical biosensors for detecting various hormones, including cortisol, sex hormones (estradiol, progesterone, testosterone), insulin, thyroid-stimulating hormone, and growth hormone. Focusing on potential analytical applications across various fields, particularly in clinical research and the study of innovative, eco-sustainable nanomaterials, the following works have been conducted: the development of a simple electrochemical immunosensor for detecting D-dimer protein in human plasma samples; the creation of a novel voltammetric immunosensor for point-of-care detection of salivary MMP-8; and the development of novel chitosan-lignin mixed nanoparticles, prepared using nanoprecipitation techniques, which exhibited unique chemo physical and electrochemical properties. In the following chapters I reported the cited papers, subdivided depending on the application field.