Abstract
Multifunctional nanoparticles, which incorporate diagnostic (quantum dots, magnetic, metallic, polymeric and silica nanoparticles) and/or therapeutic (magnetic and metallic nanoparticles) properties, are in the process of development. They have been used in vivo to protect the drug entity in the systemic circulation, restrict access of the drug to the chosen sites and to deliver the drug at a controlled and sustained rate to the site of action. The surface of gold nanoparticles can be tailored by ligand functionalization to selectively bind biomarkers. Thiol-linking of DNA and chemical functionalization of gold nanoparticles for specific protein/antibody binding are the most common approaches. Several methods have been utilized for detecting AuNPs such as scanometric, fluorescence, colorimetric, surface-enhanced Raman scattering and electrochemical techniques. These unique aspects have allowed the development of novel AuNP-based assays for clinical diagnostics which promise increased sensitivity and specificity, multiplexing capability, and short turnaround times. This article focuses on nanoparticle, application in clinical diagnosis and therapeutics especially with reference with gold nanoparticle.