Empirical Modelling And Experimental Investigation On Absorption Spectra Of Colloidal Metal Nanoparticles And Quantum Dots Suspended In Ionic Surrounding Media

Mehrdel, Baharak (2019) Empirical Modelling And Experimental Investigation On Absorption Spectra Of Colloidal Metal Nanoparticles And Quantum Dots Suspended In Ionic Surrounding Media. PhD thesis, Perpustakan Hamzah Sendut.

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Abstract

This study investigates the influence of the nanoparticle size and refractive index of non - absorbent ionic surrounding media on the optical absorption spectra of noble metal nanoparticles ( Au, Ag ; excited emission) and semiconductor quantum dots ( CdSe/ZnS ; spontaneous emission) designed for sensing application. Numerous studies on experimental research have shown that, the optical absorption spectra of noble metal nanoparticles and quantum dots are strongly dependent on the nanoparticle size and refractive index of surrounding media, while weakly dependent on the refractive index of non - absorbent ionic surrounding media which gradually change from 1.33 to 1.34. However, there is still lack of information on the effect of identity of the surrounding media for noble metal nanoparticles and quantum dots as a function of particle size. To address this issue, the first derivative method was applied to simulated absorption spectra of Mie theory and experimental absorption spectra of nanoparticles to quantitatively evaluate the spectra resonance. To determine the influence of identity of ionic surrounding media on the measured optical spect ra for noble metal nanoparticles and semiconductor quantum dots, a series of experiments were performed using sodium chloride (NaCl), sodium hydroxide (NaOH), and phosphate buffered saline (PBS). Specifically, the Mie theory was employed, with minor modifi cation to the dielectric constant of metal nanoparticles (Lorentz - Drude size dependent) followed by the first derivative method treatment to analyse the optical absorption spectra. R esults from the first derivative method showed the theoretical

Item Type:	Thesis (PhD)
Subjects:	Q Science > QC Physics > QC1 Physics (General)
Divisions:	Pusat Pengajian Sains Fizik (School of Physics) > Thesis
Depositing User:	Mr Hasmizar Mansor
Date Deposited:	28 Oct 2026 03:53
Last Modified:	02 Nov 2026 01:11
URI:	http://eprints.usm.my/id/eprint/65184

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