Optical properties of normal and 'giant' multishell CdSe quantum dots for potential application in material science

Nga, Pham Thu; Chinh, Vu Đuc; Hanh, Vu Thi Hong; Nghia, Nguyen Xuan; Dzung, P. T.; Barthou, Carlos; Bénalloul, P.; Laverdant, Julien; Maître, Agnès

doi:10.1504/ijnt.2011.038211

Cited by 12 publications

(14 citation statements)

References 17 publications

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“…AChE enzymes (EC 3.1.1.7, activity unit: 500 U/0.7 mg) and S-acetylthiocholine iodide (ATChI) is purchased from Sigma-Aldrich. The ATCh was prepared from ATChI [6]. The four types of pesticides: TF; CH; AT; CS were obtained from Vietnam Plant Protection Department (PPD).…”

Section: Methodsmentioning

confidence: 99%

“…Organophosphorus (OP) compounds, carbamates, or neonicotinoids are widely used in plant protection because of the efficiency for insect killing, easy synthesis, and low cost. The above pesticide residues are harmful to the environment, human health, and animals through the nervous system poisoning by the way of inhibiting the activity of AChE, the most important enzyme involved in nerve transmission [1,6]. The principal role of AChE is the termination of nerve impulse transmission at cholinergic synapses by rapid hydrolysis of the neurotransmitter acetylcholine (ACh) -each molecule of AChE degrades about 25000 molecules of ACh per second, leading to in vivo accumulation of ACh, and then resulting in serious impairment on nerve functions [2].…”

Section: Introductionmentioning

confidence: 99%

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Sensitive Organophosphorus and Carbamate Pesticides Biosensor Based on Acetylcholinesterase and CdZnSe/ZnS Ternary Alloy Quantum Dots

Hải¹,

Yen²,

Giang³

et al. 2014

Comm. in Phys.

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This report presents the results of ternary alloy quantum dots (TQDs) manufacturing and its superior optical properties to fabricate the biosensor for pesticide detection. The explanation for the changes in PL intensity based on the change of electronic charges that alters the pH value of the surrounding environment, and the types of interaction on the surface of CdZnSe/ZnS TQDs were discussed. We show the decomposition process of the indicator (ATCh) with the catalysis from acetylcholinesterase enzyme (AChE) that inhibited by organophosphorus and carbamate pesticides including Trichlorfon (TF), Cypermethrin (CH), Abamectin (AT), and Carbosulfan (CS) with concentrations from 0.05 ppm to 10 ppm.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Sensitive Organophosphorus and Carbamate Pesticides Biosensor Based on Acetylcholinesterase and CdZnSe/ZnS Ternary Alloy Quantum Dots

Hải¹,

Yen²,

Giang³

et al. 2014

Comm. in Phys.

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“…The CdZnSe TQDs were synthesized with a constant precursor ratio of Cd 0.2 Zn 0.8 Se. This method is adapted from an existing work for CdSe quantum dots [5,6]. We used ultra-pure nitrogen flow for all synthetic routes.…”

Section: Ii1 Synthesis Of Cdznse Core and Cdznse/zns Core/shell Tqdsmentioning

confidence: 99%

“…Some work reported give the finding that TQDs may represent a new route to achieve the next generation of QDs [5]. The widely tunable emissions of Cd x Zn 1−x Se alloy QDs in the range of wavelengths from 534 to 620 nm, are reported [6]. The compositions of TQDs were estimated based on their sizes and band gap energy.…”

Section: Introductionmentioning

confidence: 99%

Mechanism to Detect Pesticide Residues in Tealeaves Based on CdZnSe/ZnS Ternary Alloy Quantum Dots

Hải¹,

Yen²,

Giang³

et al. 2015

Comm. in Phys.

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In this report, we present the optical properties of the biosensors fabricated from CdZnSe/ZnS quantum dots. The optical properties such as absorption and emission of the ternary quantum dots before and after coupling with the protein molecules like streptavidine (SA) and acetylcholinesterase enzymes (AChE), to form a biosensor structure, will be presented. In particular, the changes in luminescence intensity according to the pH value of the solution environment containing biosensor have been considered, before and after the presence of pesticides. The changes in luminescence intensity of the biosensor after the presence of pesticide over time from 2 seconds to 26 minutes were also surveyed. We have been carried out the tests to determine the trace amounts of commercial pesticides like Motox 5EC, containing 5% cypermethrin and Tungatin 10 EC, containing 10% abamectin, on the real samples of tealeaves. Some characteristics of the relationship between composition, structure, and special optical properties of ternary alloy quantum dots will also be presented. These studies open up the potential applications of ternary quantum dots for agricultural production.

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“…The synthesis protocol has been described in [25,26]. A thick ZnS shell (19 monolayers) is fabricated in order to protect the nanocrystal.…”

Section: Quantum Yield Of Nanocrystalsmentioning

confidence: 99%

Experimental Determination of the Fluorescence Quantum Yield of Semiconductor Nanocrystals

et al. 2011

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Many studies have considered the luminescence of colloidal II–VI nanocrystals, both in solution at a collective scale and at an individual scale by confocal microscopy. The quantum yield is an important figure of merit for the optical quality of a fluorophore. We detail here a simple method to determine the quantum yield of nanocrystals in solution as a function of the absorption. For this purpose, we choose rhodamine 101 as a reference dye to measure the nanocrystal fluorescence quantum yield. The influence of the concentration on quantum yield is therefore studied for both the reference and the solutions of nanocrystals and is found to be critical for the acuity of the method. Different types of nanocrystals are studied to illustrate different quantum yield evolutions with the concentration.

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Optical properties of normal and 'giant' multishell CdSe quantum dots for potential application in material science

Cited by 12 publications

References 17 publications

Sensitive Organophosphorus and Carbamate Pesticides Biosensor Based on Acetylcholinesterase and CdZnSe/ZnS Ternary Alloy Quantum Dots

Sensitive Organophosphorus and Carbamate Pesticides Biosensor Based on Acetylcholinesterase and CdZnSe/ZnS Ternary Alloy Quantum Dots

Mechanism to Detect Pesticide Residues in Tealeaves Based on CdZnSe/ZnS Ternary Alloy Quantum Dots

Experimental Determination of the Fluorescence Quantum Yield of Semiconductor Nanocrystals

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