Investigation of Performance Parameters of Spherical Gold Nanoparticles in Localized Surface Plasmon Resonance Biosensing

Abstract

In this paper, we present numerical and experimental results on Localized Surface Plasmon Resonance (LSPR) refractive index (RI) sensitivity, Figure of Merit (FoM), and penetration depth (dp) dependence on spherical gold nanoparticles (AuNPs) size, and the effects of AuNP dimer interparticle distance (ds) studied numerically. These parameters were calculated and observed for d = 20, 40, 60, 80, and 100 nm diameter spherical AuNPs. Our investigation shows d = 60 nm AuNPs give the best FoM. The AuNP dimer interparticle distance can significantly influence the RI sensitivity. Therefore, the effect of distances between pairs of d = 20 nm and 60 nm AuNPs is shown. We discuss the importance of penetration depth information for AuNPs functionalized with aptamers for biosensing in the context of aptamer size.

Gold Nanoparticles in Nanobiotechnology: From Synthesis to Biosensing Applications

“…Gold nanoparticles (AuNPs) are frequently employed as signal transducers in biosensing . The binding of the target analyte to the functionalized gold nanoparticles (AuNPs) results in alterations in the local refractive index and the interparticle distance . The modifications in the surrounding conditions of the nanoparticle lead to a modification in the wavelength of their surface plasmonic resonance (SPR) or a variation in their visual appearance, which can be detected or measured using spectroscopic methods .…”

“… 22 The binding of the target analyte to the functionalized gold nanoparticles (AuNPs) results in alterations in the local refractive index and the interparticle distance. 89 The modifications in the surrounding conditions of the nanoparticle lead to a modification in the wavelength of their surface plasmonic resonance (SPR) or a variation in their visual appearance, which can be detected or measured using spectroscopic methods. 90 The optical response described here is the fundamental principle behind numerous colorimetric and plasmonic biosensors.…”