Recent Progress in the Electrochemical Detection of Disease‐Related Diagnostic Biomarkers
Over 60% of the information held on the patient record comes from diagnostic tests, according to an estimation by the European Diagnostic Manufacturers Association. Because they are often time consuming and expensive (or even not yet existing), significant effort is currently directed towards developing simple, fast and cheap diagnostic tests. However, adding simplicity, speed and cost effectiveness to the reliability of such tests is one of the main challenges of clinical diagnostics. Electrochemical sensors for detection of proteins, DNA sequences, or cells are regarded by many as appropriate tools to overcome this challenge. Therefore, the present chapter offers an overview of electrochemical sensors able to detect markers of cancer, cardiac diseases, acquired immunodeficiency syndrome, hepatitis, rheumathoid arthritis, celiac disease, and urinary tract infection. The use of nanotechnology in the development of the sensors is one of the main trends observed. Nanotechnology provides a gain in sensitivity but can also lead to reproducibility and reliability problems, high costs, and unclear sensor structure and mechanism of signal generation. Replacing antibodies with aptamers is another trend observed. Compared to antibodies, aptamers are easier to obtain and more robust. Lab‐on‐a‐chip approaches, multiplexing and total diagnosis systems integrating different biorecognition principles on the same platform (e.g. DNA hybridization and immunosensing) appear as part of the future of electrochemical sensors for clinical diagnosis. Adding tests with real samples to the characterization of the sensors with standard solutions is another characteristic of the recent research in the field. Such tests are welcome as they are the only way to eventually achieve a significant acceptance of these sensors outside the research community involved in their development. Electrochemical sensors are still in need of such acceptance.