ABSTRACT
The unprecedented materialistic and optoelectronic properties of various nanomaterials, including nanoparticles [NPs], render them suitable for further exploration as label-free sensing tools with improved sensitivity or specificity and vast applications in medicine, including point-of-care diagnostics. Most NPs can be synthesized with the precise physicochemical characteristics required for sensing. Gold NPs [AuNPs] have emerged as the foremost candidate of the family of NPs from noble metals (Au, Ag, Pt, etc.) for biosensing purposes. Some advantages of AuNPs are biocompatibility, tunability and known optoelectronic behavior, relative ease of production, presence of efficient functionalization techniques, and availability in different sizes or shapes. The bigger AuNPs scatter more due to a larger scattering cross section. As a result, there is considerable broadening and flattening of the absorbance peak with increasing size of the particles. The shape of AuNPs is an important attribute in determining the localized surface plasmon resonance.
