Advanced Electrochemical and Opto-Electrochemical Biosensors for Quantitative Analysis of Disease Markers and Viruses

The recent global health crisis caused by the SARS-CoV-2 pandemic has dramatically highlighted the urgent need for rapid and reliable analytical devices and methods that are capable of carrying out a large number of quantitative analyses, not only in centralized laboratories and core facilities but also on site, at the patients’ bed-side, or at the medical doctor's practice in view of the point-of-care testing (PoCT). Especially for the case of immunological tests, this recent experience has revealed a relevant gap between the classical ELISA (which provides quantitative and reliable responses, although it must be performed in a centralized laboratory by qualified personnel) and strip lateral flow tests (which are suitable for decentralized use, although they provide only qualitative information that is often lacking the required sensitivity and specificity). New analytical devices are therefore highly sought which will fill this gap, combining the capability to provide quantitative analytical responses with fast and user-friendly applicability. The advantages typical of electrochemical and optical biosensors (low cost and easy transduction) can nowadays be complemented in terms of improved sensitivity by combining electrochemistry (EC) with optical techniques such as electrochemiluminescence (ECL), EC/surface-enhanced Raman spectroscopy (SERS), and EC/surface plasmon resonance (SPR). The present Special Issue is devoted to exploring new approaches, solutions, and applications in electrochemical, optical and opto-electrochemical biosensors suitable for the quantitative detection of disease markers with focus on frontiers and challenges in immunochemical or genetic analysis and virus detection.