Electrochemical sensing of analytes in saliva: Challenges, progress, and perspectives

The detection of analytes in human saliva is an important task for real-life sensing device applications, as well as a challenging issue due to its high viscosity and the presence of interfering components. In particular, a sensing strategy without biomolecules (antibody, aptamer, or an enzyme) specific to target analytes provides an opportunity to develop a simpler and more economical device that is crucial for practical purposes. This review article focuses on the challenges associated with the electrochemical sensing of analytes in saliva, highlighting the saliva properties and its complications in electrochemical sensing. This article also aims to provide critical reviews on recent advancements in biomolecule-free electrochemical detection in saliva, focusing on the design, methodology, saliva collection and treatment, and potential solutions. Moreover, this article provides a future perspective that would be helpful for fellow researchers in overcoming the potential drawbacks corresponding to the detection of analytes in saliva in the near future.