Gold nanoparticles for salivary-based sensors: A review

Advancements in nanotechnology integrated with biomedical diagnostics have facilitated substantial progress in non-invasive health monitoring, with salivary biosensors utilizing gold nanoparticles (AuNPs) emerging as a novel approach for rapid, sensitive, and user-friendly point-of-care testing. This review article demonstrates how researchers utilize the distinctive physicochemical qualities of AuNPs, specifically their plasmonic responsiveness and bioconjugation ability, to improve diverse biosensing techniques. Rather than traditional blood-based diagnostics, AuNP-based devices utilize saliva as a molecular reservoir to monitor a variety of biomarkers such as hormones, metabolites, nucleic acids, or other analytes. The development of these biosensors extends beyond technological innovation to their incorporation into affordable, user-friendly devices that address clinical needs. Still, converting these biosensors into standardized health care diagnostic tools encounters similar challenges as other bioassays pertaining to biofluid-based complexity, burden of reproducibility, and regulatory approval. In addition to summarizing the extent of scientific and engineering accomplishments to date, this review highlights the opportunity for future implementation of AuNP-based biosensor tests in personalized medicine, advocating synergistic interdisciplinary approaches that integrate materials science, digital analytics, and device engineering to fully realize AuNP-based salivary diagnostics.