Gold Nanoparticle-based Biosensors for Point-of-Care Diagnostics: A Review of Sensing Nanoparticle Applications and Future Prospects.

Point of Care Diagnostics (POCD) is quintessential in hospitals and the healthcare sector as the secants uplift the quality of medical care and the life of a patient by facilitating quick identification of the underlying pathological condition. Nanotechnology can provide opportunities and has potential in the development of new-age sensing/diagnostic tools. Owing to extraordinary features (e.g., higher density, effective catalysis, good conduction, biocompatibility, inertness, and greater surface-to-volume ratio), gold nanoparticles (AuNPs) are frequently employed in POCT (Point-of-Care-Testing). Gold nanoparticles-based colorimetric methods are widely used in the rapid, sensitive, and selective detection of analytes/target molecules. AuNPs description is critical for their possible utility in prophylaxis, diagnostics, and treatment of an ailment. AuNPs interact with organic/inorganic target molecules to generate colorimetric shift that enables the accurate, precise, and subtle recognition of biologicals (e.g., microorganisms, cellular components, and proteins) and metal ions. This review focused on the need for AuNPs-based colorimetric application in prophylaxis, diagnostics, and treatment in healthcare and reviewed the future outlook of these AuNPs for biological applications. Different synthesis methods of AuNPs, their morphology, and characterization, including their surface functionalization, will be discussed in detail. AuNPs are very much preferable nanomaterials owing to exclusive optical, electrical, and photothermal features. AuNPsbased colorimetric biosensors are simple and possess great utility, yet these offer a robust technique to enable visual, quantitative analysis.