scholarly journals Sensitive Determination of Cetirizine Using CdS Quantum dots as Oxidase Mimic-mediated Chemiluminescence of Sulfite

2016 ◽  
Vol 5 (7) ◽  
pp. 59-62 ◽  
Author(s):  
Reza Hoseinpour Kouhestany ◽  
Seyed Naser Azizi ◽  
Parmis Shakeri ◽  
Shaghyegh Rahmani
Keyword(s):  
Quantum Dots ◽  
Limit Of Detection ◽  
Ultra Violet ◽  
Cost Effective ◽  
Pharmaceutical Journal ◽  
Water Soluble ◽  
Cds Quantum Dots ◽  
Study Results ◽  
Cds Qds

A new chemiluminescence (CL) method using cadmium sulfide quantum dots (QDs) as sensitizers is proposed for the chemiluminometric determination of cetirizine pharmaceutical formulation. CdS QDs were synthesized by using water soluble route. The nanoparticles were structurally and optically characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Ultra Violet-Visible (UV–Vis) absorption spectroscopy and scanning electron microscopy (SEM). In this study results shows that CdS quantum dots are enhancers of the weak CL emission. Trace amounts of cetirizine improved the sensitize effect of CdS quantum dots yielding a significant chemiluminescence enhancement of the Ce(IV)–SO32?–CdS QDs system. So, a new CL analysis system was selected for the determination of cetirizine. There is a good linear relationship between the relative chemiluminescence intensity and the concentration of cetirizine in the range of 1×10?9– 1×10?6 molL?1 with a correlation coefficient (R2) of 0.9963 at the optimum conditions. The limit of detection (LOD) of this system was found to be 5×10?11 M. This method is simple, sensitive and cost effective, and also is accommodating for pharmaceutical applications.Kouhestany et al., International Current Pharmaceutical Journal, June 2016, 5(7): 59-62

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.

Determination of Trace Iron in Chinese Herbal Medicine Using CdS Quantum Dots as Fluorescence Probes

2012 ◽  
Vol 455-456 ◽  
pp. 1195-1199
Author(s):  
Yun Long Zeng ◽  
Xia Fei Li ◽  
Chun Ran Tang ◽  
Hao Wen Huang ◽  
Ya Jing Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Fluorescence Probe ◽  
Copper Ion ◽  
Water Soluble ◽  
Fluorescence Probes ◽  
Cds Quantum Dots ◽  
Buffer Solution ◽  
Green Protocol ◽  
Quenching Method

A simple A green protocol for synthesis of high quality, water-soluble and biocompatible CdS QDs have been developed in aqueous solution with amylum as stabilizing agent. The QDs were characterized by AMF and spectral methods. A fluorescence quenching method was developed for determination of iron (ΙΙΙ) with water soluble CdS quantum dots (QDs) as fluorescence probe. In pH 8.5 boric acid–borax buffer solution, the QDs show a high selective to ferric ion. The common cations, such as Ca2+, Mg2+, Zn2+, Fe2+ et al, have no effect on interference but copper ion. The fluorescence intensity of the QDs decreased linearly with the iron (QDs ) concentration in the range of 200 μM to 60 nM with a detection limit of 20 nM. It has been applied to determinate of iron in Angelica, Astragalus, Shouwu, ligusticum wallichii and radix rehmanniae recen.

scholarly journals Surface-modified Colloid CdTe/CdS Quantum Dots by a Biocompatible Thiazolidine Derivative as Promising Platform for Immobilization of Glucose Oxidase: Application to Fluorescence Sensing of Glucose

2021 ◽  
Author(s):  
Rahman Hallaj ◽  
Zahra Hosseinchi
Keyword(s):  
Quantum Dots ◽  
Glucose Oxidase ◽  
Limit Of Detection ◽  
Low Cost ◽  
Fluorescence Emission ◽  
Cds Quantum Dots ◽  
Fluorescence Sensing ◽  
Experimental Conditions ◽  
Glucose Determination ◽  
Cds Qds

Abstract This work focuses on the synthesis of novel modified core-shell CdTe/CdS quantum dots (QDs) and develops as a fluorescence sensor for glucose determination. The (E)-2,2'-(4,4'-dioxo-2,2'-dithioxo-2H,2'H-[5,5'-bithiazolylidene]-3,3'(4H,4'H)-diyl)bis(3- mercaptopropanoic acid) (DTM) as a new derivative of thiazolidine was synthesized and characterized and used to surface-modification of CdTe/CdS QDs. DTM-capped CdTe/CdS QDs used to immobilization of glucose oxidase (GOD). The intensity fluorescence emission of the CdSe/CdS-DTM/GOD is highly sensitive to the concentration of H2O2 as a byproduct of the catalytic oxidation of glucose. The experimental results showed that the quenched fluorescence was proportional to the glucose concentration within the range of 10 nM − 0.32 µM under optimized experimental conditions. The limit of detection of this system was found to be 4.3 nM. Compared with most of the existing methods, this newly developed system possesses many advantages, including simplicity, low cost, and good sensitivity.

A simple and sensitive flow injection method based on the catalytic activity of CdS quantum dots in an acidic permanganate chemiluminescence system for determination of formaldehyde in water and wastewater

2016 ◽  
Vol 15 (4) ◽  
pp. 496-505 ◽  
Author(s):  
Alireza Khataee ◽  
Roya Lotfi ◽  
Aliyeh Hasanzadeh ◽  
Mortaza Iranifam
Keyword(s):  
Quantum Dots ◽  
Catalytic Activity ◽  
Flow Injection ◽  
Cds Quantum Dots ◽  
Injection Method ◽  
Water And Wastewater ◽  
Cds Qds

The intensity of emitted light from KMnO4–HCHO–CdS QDs system is linearly proportional to HCHO concentration.

Highly sensitive determination of copper (II) ions using fluorescence and chemiluminescence emissions of modified CdS quantum dots after it’s preconcentration by dispersive liquid–liquid microextraction

2017 ◽  
Vol 95 (6) ◽  
pp. 704-709 ◽  
Author(s):  
Zohreh Saeedi ◽  
Ali Lotfi ◽  
Javad Hassanzadeh ◽  
Nafiseh Bagheri
Keyword(s):  
Quantum Dots ◽  
High Yield ◽  
Cds Quantum Dots ◽  
Quenching Effect ◽  
Highly Sensitive ◽  
Cds Qds ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction ◽  
Determination Of Copper

Two highly sensitive and selective methods based on fluorescence (FL) and chemiluminescence (CL) emissions of 8-mercaptoquinoline-capped CdS quantum dots (MCQ-CdS QDs) were described for the determination of copper (II) after it’s preconcentration. High fluorescent CdS QDs, synthesized in an aqueous medium, generated a relatively intense CL emission in the presence of potassium permanganate as an oxidant. Furthermore, low quantities of copper (II) ions showed a remarkable quenching effect on both of the CL and FL emissions of MCQ-CdS QDs. Based on this effect, two selective and simple methods were established for Cu2+, and the detection limits of 0.28 and 0.026 ng mL−1 were obtained for the FL and CL methods, respectively. Also, due to the high propensity of MCQ to Cu2+, good selectivity was obtained and no sensible interfering effects from other metal ions were observed. To more sensitize the developed method, an efficient preconcentration process was designed based on the high-yield ultrasound-assisted temperature-controlled ionic liquid dispersive liquid–liquid microextraction (UA-TIL-DLLME) method. Under the optimum conditions, the extracted Cu2+ showed a suppressing effect on the FL and CL emissions of CdS QDs proportional to its initial concentration over the ranges of 0.008–1.4 and 0.001–1.4 ng mL−1, respectively. The limits of detection of 3.7 and 0.37 pg mL−1, respectively, were also achieved. The established methods showed great features and were satisfactorily applied to the monitoring of ultratrace Cu2+ in some different environmental samples.

Turn-off–on fluorescence probe based on 3-mercaptopropionic acid-capped CdS quantum dots for selective and sensitive lysozyme detection

RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 85795-85801 ◽  
Author(s):  
Xiaotong Liu ◽  
Weidan Na ◽  
Zhengyi Qu ◽  
Xingguang Su
Keyword(s):  
Quantum Dots ◽  
Fluorescence Probe ◽  
Fluorescence Assay ◽  
Cds Quantum Dots ◽  
Mercaptopropionic Acid ◽  
Cds Qds

The fluorescence of CdS QDs was first quenched by hemoglobin and then restored with the increasing concentration of the lysozyme in a certain range. Therefore, a fluorescence assay for the determination of lysozyme was established.

A novel permanganate–morin–CdS quantum dots flow injection chemiluminescence system for sensitive determination of vancomycin

RSC Advances ◽  
2015 ◽  
Vol 5 (101) ◽  
pp. 82645-82653 ◽  
Author(s):  
Alireza Khataee ◽  
Roya Lotfi ◽  
Aliyeh Hasanzadeh
Keyword(s):  
Quantum Dots ◽  
Flow Injection ◽  
Cds Quantum Dots ◽  
Sensitive Determination ◽  
Cds Qds ◽  
Flow Injection Chemiluminescence

The intensity of emitted light from KMnO4−morin−CdS QDs system is described as a novel chemiluminescence (CL) reaction. The CL intensity of this CL system was remarkably enhanced in the presence of vancomycin.

Enhanced electrochemiluminescence of CdS quantum dots capped with mercaptopropionic acid activated by EDC for Zika virus detection

The Analyst ◽  
2021 ◽  
Author(s):  
Hui-Jun Zhang ◽  
Jin Zhu ◽  
Ning Bao ◽  
Shou-Nian Ding
Keyword(s):  
Quantum Dots ◽  
Zika Virus ◽  
Virus Detection ◽  
Cds Quantum Dots ◽  
Mercaptopropionic Acid ◽  
Sandwich Type ◽  
Cds Qds

The mechanism of enhanced ECL of MPA@CdS QDs by EDC activation was investigated, and a sandwich-type ECL immunosensor has been designed for Zika virus detection.

scholarly journals Pitfalls in the Immunochemical Determination of β‑Lactam Antibiotics in Water

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 298
Author(s):  
Alexander Ecke ◽  
Rudolf J. Schneider
Keyword(s):  
Limit Of Detection ◽  
Cost Effective ◽  
Enzyme Linked Immunosorbent Assay ◽  
Degree Of Hydrolysis ◽  
Site Analysis ◽  
Antibody Recognition ◽  
Immunochemical Determination ◽  
Key Factor ◽  
Lactam Ring

Contamination of waters with pharmaceuticals is an alarming problem as it may support the evolution of antimicrobial resistance. Therefore, fast and cost-effective analytical methods for potential on-site analysis are desired in order to control the water quality and assure the safety of its use as a source of drinking water. Antibody-based methods, such as the enzyme-linked immunosorbent assay (ELISA), can be helpful in this regard but can also have certain pitfalls in store, depending on the analyte. As shown here for the class of β-lactam antibiotics, hydrolysis of the β‑lactam ring is a key factor in the immunochemical analysis as it influences antibody recognition. With the antibody used in this study, the limit of detection (LOD) in the immunoassay could be significantly reduced by hydrolysis for the five tested penicillins, with the lowest LOD for carbenicillin (0.2 nmol/L) and the greatest impact on penicillins G and V (reduction by 85%). In addition to enhanced quantification, our strategy also provides access to information about the degree of hydrolysis in water samples as shown for the most abundant penicillin amoxicillin.

scholarly journals Immobilization-Free Electrochemical Sensor Coupled with a Graphene-Oxide-Based Aptasensor for Glycated Albumin Detection

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 85
Author(s):  
Wassa Waiwinya ◽  
Thitirat Putnin ◽  
Dechnarong Pimalai ◽  
Wireeya Chawjiraphan ◽  
Nuankanya Sathirapongsasuti ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Detection Method ◽  
Limit Of Detection ◽  
Glycated Albumin ◽  
Cost Effective ◽  
Logarithmic Scale ◽  
Electrochemical Aptasensor ◽  
Alternative Approach

An immobilization-free electrochemical sensor coupled with a graphene oxide (GO)-based aptasensor was developed for glycated human serum albumin (GHSA) detection. The concentration of GHSA was monitored by measuring the electrochemical response of free GO and aptamer-bound GO in the presence of glycated albumin; their currents served as the analytical signals. The electrochemical aptasensor exhibited good performance with a base-10 logarithmic scale. The calibration curve was achieved in the range of 0.01–50 µg/mL. The limit of detection (LOD) was 8.70 ng/mL. The developed method was considered a one-drop measurement process because a fabrication step and the probe-immobilization process were not required. This simple sensor offers a cost-effective, rapid, and sensitive detection method, and could be an alternative approach for determination of GHSA levels.

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