One-step hydrothermal synthesis of thioglycolic acid capped CdS quantum dots as fluorescence determination of cobalt ion

Abstract

Highly luminescent CdS quantum dots capped with thioglycolic acid (TGA@CdS QDs) were synthesized from cadmium chloride and thiourea as cadmium and sulfur sources via simple hydrothermal method. The room temperature photoluminescence (RTPL) properties of TGA@CdS QDs were investigated. The results indicate that the polarity of the solvent and the surface trap state resulted in the broadness Stokes shift between the maximum absorption wavelength and the emission wavelength of TGA@CdS QDs. The Co2+ sensing properties of fluorescence determination were investigated using TGA@CdS QDs. The as-synthesized CdS QDs exhibits the excellent selectivity and sensitivity of fluorescence quenching for cobalt ion (Co2+). The limit of detection (LOD) is as low as 0.05 μM which is much lower than maximum limit of cobalt ions in drinking water. The linear response range of Co2+ was from 0.5 to 80 μM. The sensing system revealed the advantages of low detection limit, excellent selectivity, high sensitivity, convenience and low cost. The color change of CdS QDs shows potential applications in the detection of Co2+.

Ultrasmall aqueous starch-capped CuS quantum dots with tunable localized surface plasmon resonance and composition for the selective and sensitive detection of mercury(ii) ions

“…17 Therefore, it is vital to develop a simple route for the preparation of CuS QDs in water. Over the past few years, QDs have been widely used in the detection of transition metal ions 36 and heavy metals ions. 37 Based on their tunable optical properties, cation exchange reactions, sulfur rich nature and quantum size effect we hypothesize that CuS QDs might function as a novel Hg 2+ ion sensor, with distinct advantages over conventional analytical techniques and other nanomaterial-based sensors in terms of cost, solubility and environmental benignity.…”

Citric Acid Capped CdS Quantum Dots for Fluorescence Detection of Copper Ions (II) in Aqueous Solution

“…The CdS QDs was synthesized using citric acid as the surface modification through hydrothermal method [42,48]. In brief, 0.25 mmol CdCl 2 ·2.5H 2 O and 0.5 mmol citric acid were dissolved in 50 mL distilled water under magnetic stirring.…”

“…Besides, semiconductor QDs can be further modified by surface ligands and therefore obtain specific fluorescent prober. So far, these surface ligands with functional groups, including citrate [42], L-cysteine [43,44], cysteamine [45,46], 3-mercaptopropionic acid [47], thioglycolic acid [48], glutathione [49] and peptide [50], which have been studied in CdS QDs modification and analytical application. Therefore, it could be expected that surface ligands modified CdS QDs as fluorescence probe for detecting Cu 2+ show promise.…”

Kajian terhadap Sifat Optik Titik Kuantum Kadmium Sulfida pada Pelbagai Nilai pH dan Modifikasi Permukaan dengan Asid Tioglikolik

“…Pereputan pendarflour bagi CdS-TGA pada pH8, pH9 dan pH10 Pada umumnya, pereputan bieksponen boleh mencerap TK samada daripada iluminasi jenis radioaktif ataupun tidak. Komponen yang laju (τ 1 ) adalah daripada iluminasi bukan-radioaktif seperti kecacatan permukaan yang terdiri daripada lubang dan elektron yang terperangkap dan penggabungan kembali eksiton, juga mengurangkan nilai hasil kuantum (HQ) yang juga, selalunya mempunyai jangka hayat yang lama (Durmusoglu et al 2017;Wang et al 2018). Komponen yang perlahan (τ 2 ) adalah daripada lubang dan elektron yang bergabung kembali iaitu yang mengalami masa rehat yang lebih lama dan mempunyai jangka hayat yang pendek hasil daripada pereputan radioaktif yang disebabkan oleh gabungan semula tepianjalur atau penggabungan semula elektron-lubang pada permukaan (Durmusoglu et al 2017;Wang et al 2018).…”

“…Komponen yang laju (τ 1 ) adalah daripada iluminasi bukan-radioaktif seperti kecacatan permukaan yang terdiri daripada lubang dan elektron yang terperangkap dan penggabungan kembali eksiton, juga mengurangkan nilai hasil kuantum (HQ) yang juga, selalunya mempunyai jangka hayat yang lama (Durmusoglu et al 2017;Wang et al 2018). Komponen yang perlahan (τ 2 ) adalah daripada lubang dan elektron yang bergabung kembali iaitu yang mengalami masa rehat yang lebih lama dan mempunyai jangka hayat yang pendek hasil daripada pereputan radioaktif yang disebabkan oleh gabungan semula tepianjalur atau penggabungan semula elektron-lubang pada permukaan (Durmusoglu et al 2017;Wang et al 2018). Perbandingan amplitud komponen laju (B 1 ) dan perlahan (B 2 ) boleh memberi informasi mengenai perubahan mekanisme pendarfluor selepas proses seperti pertumbuhan bahagian luar TK juga pertukaran ligan (Durmusoglu at al.…”