Fluorescence intensity and lifetime quenching of ceria nanoparticles as optical sensor for tiny metallic particles

Abstract

Effat Samir, Nader Shehata, Ishac Kandas, "Fluorescence intensity and lifetime quenching of ceria nanoparticles as optical sensor for tiny metallic particles,"Abstract. Ceria nanoparticles are studied as optical probe for different types of tiny metallic particles using fluorescence quenching technique. The synthesized ceria nanoparticles are characterized by having formed charged oxygen vacancies, which can be considered as the main receptors for the used tiny metallic particles to be sensed or absorbed. Under near-UV excitation, the visible fluorescent emission intensity is found to be reduced with increasing the concentration of the studied tiny metallic particles in an aqueous solution. To emphasize the optical sensing process, ceria nanoparticles fluorescence lifetime measurements were demonstrated before and after adding the tiny metallic particles. In addition, Stern-Volmer constants, which are considered as an indication for the sensitivity to quenchers, have been calculated for the used ceria nanoparticles and found to be 1.645, and 0.768 M −1 for both lead and iron sensing, respectively. This work could be further helpful as sensitive optical sensors in both biomedical and environmental applications.

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“…Figure 4 shows the fluorescence visible emission spectrum under the optical excitation of 430 nm. The emitted fluorescence emission spectrum of ceria NPs is according to the molecular transition of 5d–4f [ 28 ]. The states were analyzed through the experimental verification of fluorescence quenching results, as presented in Figure 5 , according to the static quenching of the radicals inside the hydrogen peroxide via the O-vacancies centers inside the synthesized ceria nanoparticles [ 40 ].…”

“…One selected parameter of water quality monitoring is the detection of hydrogen peroxide pollutants in water, which is a measure of free radical formation in water. Additionally, our protocol is applied along with experimental sensing measurements using cerium oxide (ceria) nanoparticles as an active, static sensing media for pollutants, such as hydrogen peroxide, through a visible fluorescence quenching mechanism excited by a violet optical source [ 28 ].…”