Facile Synthesis and Properties of Aqueous CdTe Quantum Dots for High-Sensitive Copper (II) Ion Detection

NANO ◽  
2017 ◽  
Vol 12 (12) ◽  
pp. 1750151 ◽  
Author(s):  
Yue Zheng ◽  
Hengshan Tang ◽  
Xiaoyu Wang ◽  
Ya Di ◽  
Kunling Lu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Limit Of Detection ◽  
Tap Water ◽  
High Sensitivity ◽  
Cdte Quantum Dots ◽  
Reaction Conditions ◽  
One Pot ◽  
Sensing System ◽  
Cdte Qds ◽  
Transmission Electron

The synthesis of aqueous MPA-capped CdTe quantum dots (QDs) via a facile one-pot route was developed. The particle size, optical properties and crystal structure of the as-synthesis QDs were investigated by transmission electron microscopy (TEM), Fourier transform infrared (FTIR), UV-vis absorption and photoluminescence (PL) spectra, respectively. Meanwhile, the effect of reaction conditions, including reaction time, pH and the quantity of sodium citrate (SC) on the growth of CdTe QDs were discussed. Then, the obtained CdTe QDs were successfully used for the detection of trace Cu[Formula: see text] with high sensitivity and excellent selectivity. The fluorescence intensity of CdTe QDs with Cu[Formula: see text] concentration showed a linear relationship in the range from [Formula: see text] mol/L to [Formula: see text][Formula: see text]mol/L. The correlation coefficient (R) is 0.9980 and limit of detection (LOD) is [Formula: see text][Formula: see text]mol/L. Moreover, the concentration of Cu[Formula: see text] in tap water samples was determined based on this sensing system and the recovery test was satisfactory.

scholarly journals Dual-Emission Fluorescence Probe Based on CdTe Quantum Dots and Rhodamine B for Visual Detection of Mercury and Its Logic Gate Behavior

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 713
Author(s):  
Yuefeng Gao ◽  
Sai Xu ◽  
Zhijian Liu ◽  
Kezhen Yu ◽  
Xinxiang Pan
Keyword(s):  
Quantum Dots ◽  
Rhodamine B ◽  
Visual Detection ◽  
Fluorescence Probe ◽  
Limit Of Detection ◽  
Logic Gate ◽  
Cdte Quantum Dots ◽  
Fluorescence Signal ◽  
Dual Emission ◽  
Cdte Qds

It is urgent that a convenient and sensitive technique of detecting Hg2+ be developed because of its toxicity. Conventional fluorescence analysis works with a single fluorescence probe, and it often suffers from signal fluctuations which are influenced by external factors. In this research, a novel dual-emission probe assembled through utilizing CdTe quantum dots (QDs) and rhodamine B was designed to detect Hg2+ visually. Only the emission of CdTe QDs was quenched after adding Hg2+ in the dual-emission probe, which caused an intensity ratio change of the two different emission wavelengths and hence facilitated the visual detection of Hg2+. Compared to single emission QDs-based probe, a better linear relationship was shown between the variation of fluorescence intensity and the concentration of Hg2+, and the limit of detection (LOD) was found to be11.4 nM in the range of 0–2.6 μM. Interestingly, the intensity of the probe containing Hg2+ could be recovered in presence of glutathione (GSH) due to the stronger binding affinity of Hg2+ towards GSH than that towards CdTe QDs. Based on this phenomenon, an IMPLICATION logic gate using Hg2+/GSH as inputs and the fluorescence signal of QDs as an output was constructed.

scholarly journals A “Turn-On” Fluorescence Copper Biosensor Based on DNA Cleavage-Dependent Graphene Oxide-dsDNA-CdTe Quantum Dots Complex

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2605 ◽  
Author(s):  
Liyun Ding ◽  
Bing Xu ◽  
Tao Li ◽  
Jun Huang ◽  
Wei Bai
Keyword(s):  
Quantum Dots ◽  
Graphene Oxide ◽  
Dna Cleavage ◽  
Copper Ions ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Cdte Quantum Dots ◽  
Turn On ◽  
Cdte Qds ◽  
Transmission Electron

A novel “turn-on” fluorescent copper biosensor is developed successfully based on the graphene oxide (GO)-dsDNA-CdTe quantum dots (QDs) complex via chemical crosslink method. The optical and structure properties of GO-dsDNA-CdTe QDs complex are studied by fluorescence (FL) spectra and transmission electron microscopy (TEM) in detail. It is demonstrated that the fluorescence quenching of CdTe QDs is a process of fluorescence resonance energy transfer (FRET) due to the essential surface and quenching properties of two-dimensional GO. Copper ions induce the catalytic reaction of DNA chain and irreversibly break at the cleavage site, which will cause the G-quadruplex formation, moreover further result in the CdTe QDs separated from GO and restored its fluorescence. Therefore, a significant recovery effect on the fluorescence of the GO-dsDNA-CdTe QDs complex is observed in the presence of copper ions. The fluorescence responses are concentration-dependent and can be well described by a linear equation. Compared with other metal ions, the sensor performs good selectivity for copper ions.

Hydrothermal Synthesis of Polyethyleneimine Modified Carbon Quantum Dots for Sensitively Detection of Cobalt Ions

2021 ◽  
Vol 21 (4) ◽  
pp. 2099-2108
Author(s):  
Yong Zhang ◽  
Changjian Zhu ◽  
Yaqing Zhang ◽  
Na Jing ◽  
Yingte Wang
Keyword(s):  
Quantum Dots ◽  
Fluorescence Probe ◽  
Limit Of Detection ◽  
Tap Water ◽  
Average Diameter ◽  
Carbon Quantum Dots ◽  
Fluorescence Excitation ◽  
Cobalt Ions ◽  
Transmission Electron ◽  
Morphology Characteristics

In this work, fluorescent carbon quantum dots (CQDs) was prepared using natural on ions as carbon source with hydrothermal method and it was modified with polyethyleneimine (PEI). The properties of PEI modified CQDs (PEI-CQDs) were characterized by fluorescence, infrared spectroscopy and ultraviolet method, the morphology characteristics of PEI-CQDs was observed by transmission electron microscope. The results shown that the fluorescence excitation and emission wavelength were at 340 nm/462 nm, respectively. The fluorescence quantum yield was 8.68%, the average diameter of the PEI-CQDs was 2.82 nm. The infrared showed that the PEI-CQDs contained hydroxyl and amino groups on its surface. The Co2+ has selective quenching effects on fluorescence of PEICQDs, PEI-CQDs can be used for detection and analysis of Co2+ in samples. The limit of detection and linear range of Co2+ using the PEI-CQDs as fluorescence probe are 0.048 μM and 0.05–11 μM, respectively. The recovery was in the range of 97.00–100.64%. Moreover, the PEI-CQDs are also successfully utilized for monitoring the Co2+ content of tap water.

One-pot synthesis of highly luminescent N-acetyl-l-cysteine-capped CdTe quantum dots and their size effect on the detection of glutathione

2018 ◽  
Vol 42 (19) ◽  
pp. 15743-15749 ◽  
Author(s):  
Jing Wang ◽  
Daquan Li ◽  
Xinyue Liu ◽  
Yu Qiu ◽  
Xiao Peng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Size Effect ◽  
Cdte Quantum Dots ◽  
One Pot ◽  
One Pot Synthesis ◽  
Large Size ◽  
Cdte Qds

N-Acetyl-l-cysteine-capped CdTe QDs with a large size (3.68 nm) are more suitable for detecting glutathione than the small ones (1.99 nm).

scholarly journals CdTe Quantum Dots Embedded in Multidentate Biopolymer Based on Salep: Characterization and Optical Properties

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ghasem Rezanejade Bardajee ◽  
Zari Hooshyar
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Water Soluble ◽  
Cdte Quantum Dots ◽  
Fluorescence Emission Spectra ◽  
Cdte Qds ◽  
Transmission Electron ◽  
Ft Ir

This paper describes a novel method for surface modification of water soluble CdTe quantum dots (QDs) by using poly(acrylic acid) grafted onto salep (salep-g-PAA) as a biopolymer. As-prepared CdTe-salep-g-PAA QDs were characterized by Fourier transform infrared (FT-IR) spectrum, thermogravimetric (TG) analysis, and transmission electron microscopy (TEM). The absorption and fluorescence emission spectra were measured to investigate the effect of salep-g-PAA biopolymer on the optical properties of CdTe QDs. The results showed that the optical properties of CdTe QDs were significantly enhanced by using salep-g-PAA-based biopolymer.

Electrostatic repulsion strategy for highly selective and sensitive “switch–on” fluorescence sensor of ascorbic acid based on the cysteamine-coated CdTe quantum dots and cerium (IV)

2021 ◽  
Author(s):  
Yifei Guo ◽  
Jingjing Du ◽  
Jianjun Li ◽  
Ran Yang ◽  
Peter B. de Harrington ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ascorbic Acid ◽  
Hydrothermal Method ◽  
Cadmium Chloride ◽  
Fluorescence Sensor ◽  
Cdte Quantum Dots ◽  
Electrostatic Repulsion ◽  
Functional Monomer ◽  
Simple Hydrothermal Method ◽  
Cdte Qds

In this work, cysteamine-coated CdTe quantum dots (CA-CdTe QDs) were synthesized by a simple hydrothermal method employing cadmium chloride as the cadmium source and cysteamine hydrochloride as the functional monomer....

A simple paper-based approach for arsenic determination in water using hydride generation coupled with mercaptosuccinic-acid capped CdTe quantum dots

2020 ◽  
Vol 12 (21) ◽  
pp. 2718-2726
Author(s):  
Oraphan Thepmanee ◽  
Kanlaya Prapainop ◽  
Obnithi Noppha ◽  
Nuanlaor Rattanawimanwong ◽  
Weena Siangproh ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Hydride Generation ◽  
Cdte Quantum Dots ◽  
Mercaptosuccinic Acid ◽  
Cdte Qds ◽  
Arsenic Detection ◽  
Detection Probe ◽  
Arsenic Determination

Paper-based device with MSA-CdTe QDs as arsenic detection probe is presented.

scholarly journals ZnSe Quantum Dots through a Facile one Pot Synthesis Process

2015 ◽  
Vol 34 ◽  
pp. 73-78
Author(s):  
Irtiqa Syed ◽  
Santa Chawla
Keyword(s):  
Quantum Dots ◽  
Band Gap ◽  
Quantum Confinement Effect ◽  
Hexagonal Phase ◽  
Fluorescence Decay ◽  
Synthesis Process ◽  
One Pot ◽  
One Pot Synthesis ◽  
Transmission Electron ◽  
Average Size

A novel one pot synthesis approach in oleic acid medium was employed to obtain monophasic ZnSe quantum dots (QD) of average size 3.7nm. The QDs were well crystalline in hexagonal phase as revealed by x-ray diffraction and high resolution transmission electron microscopy (HRTEM) studies. The ZnSe QDs exhibit sharp emission peak in the blue (465nm) with 385picosecond fluorescence decay time. The theoretical band gap corresponding to 3.7nm ZnSe QDs matched well with the measured 3.11eV band gap of synthesized QDs which thus showed quantum confinement effect.

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

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 32 ◽  
Author(s):  
Zhezhe Wang ◽  
Xuechun Xiao ◽  
Tong Zou ◽  
Yue Yang ◽  
Xinxin Xing ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Citric Acid ◽  
Limit Of Detection ◽  
Copper Ions ◽  
High Sensitivity ◽  
Fluorescence Sensor ◽  
Cds Quantum Dots ◽  
Detection Range ◽  
Cds Qds

Citric acid capped CdS quantum dots (CA-CdS QDs), a new assembled fluorescent probe for copper ions (Cu2+), was synthesized successfully by a simple hydrothermal method. In this work, the fluorescence sensor for the detection of heavy and transition metal (HTM) ions has been extensively studied in aqueous solution. The results of the present study indicate that the obtained CA-CdS QDs could detect Cu2+ with high sensitivity and selectivity. It found that the existence of Cu2+ has a significant fluorescence quenching with a large red shifted (from greenish-yellow to yellowish-orange), but not in the presence of 17 other HTM ions. As a result, Cu2S, the energy level below the CdS conduction band, could be formed at the surface of the CA-CdS QDs and leads to the quenching of fluorescence of CA-CdS QDs. Under optimal conditions, the copper ions detection range using the synthesized fluorescence sensor was 1.0 × 10‒8 M to 5.0 × 10‒5 M and the limit of detection (LOD) is 9.2 × 10‒9 M. Besides, the as-synthesized CA-CdS QDs sensor exhibited good selectivity toward Cu2+ relative to other common metal ions. Thus, the CA-CdS QDs has potential applications for detecting Cu2+ in real water samples.

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