Fabrication of a nanomaterial-based fluorescence sensor constructed from ligand capped CdTe quantum dots for ultrasensitive and rapid detection of silver ions in aqueous samples

Hamideh Elmizadeh; Majid Soleimani; Farnoush Faridbod; GhasemRezanejade Bardajee

doi:10.1016/j.saa.2018.12.016

Fabrication of a nanomaterial-based fluorescence sensor constructed from ligand capped CdTe quantum dots for ultrasensitive and rapid detection of silver ions in aqueous samples

Spectrochim Acta A Mol Biomol Spectrosc. 2019 Mar 15:211:291-298. doi: 10.1016/j.saa.2018.12.016. Epub 2018 Dec 10.

Authors

Hamideh Elmizadeh¹, Majid Soleimani², Farnoush Faridbod³, GhasemRezanejade Bardajee⁴

Affiliations

¹ Department of Chemistry, Faculty of Science, Imam Khomeini International University (IKIU), P.O.BOX: 288, Qazvin, Iran.
² Department of Chemistry, Faculty of Science, Imam Khomeini International University (IKIU), P.O.BOX: 288, Qazvin, Iran. Electronic address: m.soleimani@sci.ikiu.ac.ir.
³ Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran, Iran.
⁴ Department of Chemistry, Payame Noor University, P.O.BOX: 19395-3697, Tehran, Iran. Electronic address: rezanejad@pnu.ac.ir.

PMID: 30562702
DOI: 10.1016/j.saa.2018.12.016

Abstract

In this study, CdTe QDs were prepared in aqueous medium and then capped with a synthetic heterocycle ligand (CdTe/L QDs) via surface modification method. Characterization of synthesized CdTe/L QDs was carried out through various analytical techniques including fluorescence spectroscopy, transmission electron microscopy (TEM), UV-Vis spectrophotometry, thermo-gravimetric (TG) analysis and Fourier transform infrared (FTIR). The fluorescence intensity of the CdTe/L QDs at 520 nm (excitation at 380 nm) was selectively quenched in the presence of trace amounts of silver ions. CdTe/L QDs were utilized as an ultrasensitive and selective fluorescent sensor for determination of trace concentrations of silver ions with a detection limit of 6.12 ± 0.11 × 10^-10 mol L^-1 and a linear range of 2.04 ± 0.10 × 10^-9 mol L^-1-3.63 ± 0.12 × 10^-7 mol L^-1. The fabricated optical sensor was also used for the measurement of silver ions in real water samples which yielded satisfactory analytical results. These results were also evaluated with inductively coupled plasma emission spectroscopy (ICP-OES). This study shows that CdTe/L QDs could have potential applications in selective and sensitive analysis of different water samples for detection of silver ions.

Keywords: Fluorescence optical sensor; Heavy metal; Quantum dots; Silver ions.