Electrochemical Impedance Spectroscopy: The Common Thread

The common thread of thirty-two years of science in my life was Electrochemical Impedance Spectroscopy (EIS). Impedance microbiology initiated this road, with interesting achievements as the development of novel technology, licensed and marketed until a few years ago. Towards the end of the 1990s, an internship at the University of Hannover, Germany, introduced me to the exciting world of biosensors, which were just becoming worldwide investigated. Particularly electrochemical biosensors, which make use of EIS, a powerful technique used to evaluate interfacial properties related to bio-recognition events, in combination with nanotechnology, sparked my passion for this field. Particularly, we developed electrochemical biosensors for the detection of glucose, dopamine, alkaline phosphatase, leishmaniasis, prothrombin time, and currently biomarkers for Parkinson's disease, which has a provisional patent pending and an interested company. Applications in agriculture led us to embark on an ambitious project, developing a biosensor for the early detection of HLB, a much-feared disease in citrus plants. While the entrepreneurial group failed to consolidate, it contributed a wealth of experience to our biosensor group. The research in microfluidics opened up also new possibilities for the development of paper-based microfluidics with electrochemical and optical biosensors, and currently, the inclusion of smart polymers as actuators, are especially interesting for personalized therapy in medicine and agroindustry. The development of nanocomposite hydrogels reinforces the polymeric matrix and improves their performance. In this context, electro-responsive hydrogels are now investigated for the development of applications as a soft-actuator in different microsystems.