High sensitivity localized surface plasmon resonance sensor of gold nanoparticles: Surface density effect for detection of boric acid

This paper presents the study on localized surface plasmon resonance (LSPR) of gold nanoparticles (AuNPs) sensor and its detection towards the presence of boric acid (H₃BO₃). Boric acid is a substance commonly used as consumer products and also been used in food preparations to increase elasticity, better texture and crispiness. However, this chemical was claimed as non-permitted preservative and additive in food preparation. In this study, spherical AuNPs were grown on quartz substrate using Seed Mediated Growth Technique (SMGT) with variations seeding process. The plasmonic responses of the AuNPs in deionized water and in various concentration of boric acid solution based on optical absorption spectra of the AUNPs samples were recorded. The changes of the resonance peak intensity and position of the spectra were used as sensing parameters. It was found that the surface density of nanoparticles grown on the AuNPs samples affected the plasmonic responses and the sensing sensitivity of the AuNPs samples.