scholarly journals Paper-Based Analytical Devices for Colorimetric and Luminescent Detection of Mercury in Waters: An Overview

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7571
Author(s):  
Carlos Bendicho ◽  
Isela Lavilla ◽  
Francisco Pena-Pereira ◽  
Inmaculada de la Calle ◽  
Vanesa Romero
Keyword(s):  
Quantum Dots ◽  
Environmental Pollutants ◽  
Toxic Metal ◽  
Carbon Quantum Dots ◽  
Metal Nanoclusters ◽  
Organic Chromophores ◽  
Main Emphasis ◽  
Medical Diagnostic ◽  
Conventional Instrumentation ◽  
Recognition Elements

Lab-on-paper technologies, also known as paper-based analytical devices (PADs), have received increasing attention in the last years, and nowadays, their use has spread to virtually every application area, i.e., medical diagnostic, food safety, environmental monitoring, etc. Advantages inherent to on-field detection, which include avoiding sampling, sample preparation and conventional instrumentation in central labs, are undoubtedly driving many developments in this area. Heavy metals represent an important group of environmental pollutants that require strict controls due to the threat they pose to ecosystems and human health. In this overview, the development of PADs for Hg monitoring, which is considered the most toxic metal in the environment, is addressed. The main emphasis is placed on recognition elements (i.e., organic chromophores/fluorophores, plasmonic nanoparticles, inorganic quantum dots, carbon quantum dots, metal nanoclusters, etc.) employed to provide suitable selectivity and sensitivity. The performance of both microfluidic paper-based analytical devices and paper-based sensors using signal readout by colorimetry and luminescence will be discussed.

A green synthetic route for the surface-passivation of carbon dots as an effective multifunctional fluorescent sensor for the recognition and detection of toxic metal ions from aqueous solution

2019 ◽  
Vol 11 (4) ◽  
pp. 490-506 ◽  
Author(s):  
K. Radhakrishnan ◽  
P. Panneerselvam ◽  
M. Marieeswaran
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Carbon Dots ◽  
Surface Passivation ◽  
Fluorescent Sensor ◽  
Toxic Metal ◽  
Carbon Quantum Dots ◽  
Synthetic Route ◽  
One Pot ◽  
Hydrothermal Methods

In this work, a green synthetic route was used to create a number of surface passivated fluorescent carbon quantum dots, which are explored as promising sensing probes, via facile one-pot hydrothermal methods.

Preparation of Carbon Quantum Dots for Fluorescence Detection of Environmental Pollutants

2019 ◽  
Vol 19 (9) ◽  
pp. 5522-5528
Author(s):  
Jingwei Zhang ◽  
Han Yin ◽  
You Shen ◽  
Maojuan Bai ◽  
Jun Wan
Keyword(s):  
Quantum Dots ◽  
Fluorescence Detection ◽  
Environmental Pollutants ◽  
Carbon Quantum Dots

Carbon Quantum Dots : Synthesis and Optronics Applications

2017 ◽  
Author(s):  
Swati S. Soley
Keyword(s):  
Quantum Dots ◽  
Carbon Quantum Dots

LUMINESCENT DETERMINATION OF SUGAR IN NATURAL HONEY

2020 ◽  
Vol 0 (4) ◽  
pp. 29-32
Author(s):  
B.M. GAREEV ◽  
◽  
A.M. ABDRAKHMANOV ◽  
G.L. SHARIPOV ◽  
◽  
...  
Keyword(s):  
Quantum Dots ◽  
Laboratory Test ◽  
Aqueous Solutions ◽  
Analytical Method ◽  
Sugar Content ◽  
Carbon Quantum Dots ◽  
Photoluminescence Intensity ◽  
Sucrose Content ◽  
Natural Honey

The photoluminescence of carbon quantum dots synthesized from natural honey and mixtures of honey and sugar has been studied. An increase in the sugar content leads to a decrease in the photoluminescence intensity without changing the shape of the luminescence spectrum of these quantum dots aqueous solutions, which is associated with a decrease in the yield of their synthesis in the sugar presence. The discovered effect can be used to detect sugar in honey. When examining five different market samples of flower honey using this method, two of them showed a significant decrease in the photoluminescence intensity. A laboratory test for compliance with GOST 19792-2017 Standard requirements established an excess of the sucrose content in these samples. Luminescent determination of sugar in honey does not require complicated equipment and can be used to develop a new analytical method for determining the sugar content in counterfeit natural honey.

Detection of Glucose in Human Serum Based on Silicon Dot Probe

2020 ◽  
Vol 16 (6) ◽  
pp. 744-752
Author(s):  
Kuan Luo ◽  
Xinyu Jiang
Keyword(s):  
Quantum Dots ◽  
Blood Glucose ◽  
Human Serum ◽  
Organic Dyes ◽  
Limit Of Detection ◽  
Fasting Blood Glucose ◽  
Glucose Biosensor ◽  
Metal Nanoclusters ◽  
Glucose Levels ◽  
Highly Sensitive

Background: Diabetes Mellitus (DM) is a major public metabolic disease that influences 366 million people in the world in 2011, and this number is predicted to rise to 552 million in 2030. DM is clinically diagnosed by a fasting blood glucose that is equal or greater than 7 mM. Therefore, the development of effective glucose biosensor has attracted extensive attention worldwide. Fluorescence- based strategies have sparked tremendous interest due to their rapid response, facile operation, and excellent sensitivity. Many fluorescent compounds have been employed for precise analysis of glucose, including quantum dots, noble metal nanoclusters, up-converting nanoparticles, organic dyes, and composite fluorescent microspheres. Silicon dot as promising quantum dots materials have received extensive attention, owing to their distinct advantages such as biocompatibility, low toxicity and high photostability. Methods: MnO2 nanosheets on the Si nanoparticles (NPs) surface serve as a quencher. Si NPs fluorescence can make a recovery by the addition of H2O2, which can reduce MnO2 to Mn2+, and the glucose can thus be monitored based on the enzymatic conversion of glucose by glucose oxidase to generate H2O2. Therefore, the glucose concentration can be derived by recording the fluorescence recovery spectra of the Si NPs. Results: This probe enabled selective detection of glucose with a linear range of 1-100 μg/mL and a limit of detection of 0.98 μg/mL. Compared with the commercial glucometer, this method showed favorable results and convincing reliability. Conclusion: We have developed a novel method based on MnO2 -nanosheet-modified Si NPs for rapid monitoring of blood glucose levels. By combining the highly sensitive H2O2/MnO2 reaction with the excellent photostability of Si NPs, a highly sensitive, selective, and cost-efficient sensing approach for glucose detection has been designed and applied to monitor glucose levels in human serum with satisfactory results.

Recent Trends in Development of Nanomaterials Based Green Analytical Methods for Environmental Remediation

2020 ◽  
Vol 16 ◽  
Author(s):  
Sidra Amin ◽  
Amber R. Solangi ◽  
Dilawar Hassan ◽  
Nadir Hussain ◽  
Jamil Ahmed ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Environmental Remediation ◽  
Environmental Chemistry ◽  
Limit Of Detection ◽  
Environmental Pollutants ◽  
Toxic Metal ◽  
Electrochemical Analysis ◽  
Good Choice ◽  
Nano Materials ◽  
Limit Of Quantification

Background: In recent years, the occurrence and fate of environmental pollutants has been recognized as one of the emerging issues in environmental chemistry. A survey documented about a wide variety of these pollutants, which are often detected in our environment and these are major cause of shortened life spans and the global warming. These pollutants include toxic metal, pesticides, fertilizers, drugs and dyes released into soil and major water bodies. The presence of these contaminants causes major disturbance in eco-system’s balance. To tackle these issues many technological improvements are made to detect minute contaminations. The latest issue being answered by the scientists is the use of green nano materials as sensors which are economical, instant and give much better results at low concentrations and can be used for the field measurements resulting in no dangerous by-product that could lead to more environmental contamination. Nano materials are known for their wide band gap, enhanced physical and optical properties with option of tuneablity as per need, by optimizing certain parameters. They are proved to be good choice for analytical/optical sensors with high sensitivity. Objective: This review holds information about multiple methods that use green nanomaterials for the analytical assessment of environmental pollutants. UV-Vis spectrophotometry and electrochemical analysis using green and reproducible nanomaterials are the major focus of this review article. To date, there are number of spectrophotometric and electro chemical methods available that have been used for the detection of environmental pollutants such as toxic metals, pesticides and dyes. Conclusion: The use of nanomaterials can drastically change the detection limits due to having large surface area, strong catalytic properties, and tunable possibility. With the use of nano materials, lower than the marked limit of detection and limit of quantification were seen when compared with previously reported work. The used nano-materials could be washed, dried, and reused, which makes the methods more proficient, cost effective and environmentally friendly.

scholarly journals Highly sensitive detection of CTLA‑4‑positive T‑cell subgroups based on nanobody and fluorescent carbon quantum dots

2019 ◽  
Author(s):  
Wu Wang ◽  
Xiaoqiong Hou ◽  
Xiaomei Yang ◽  
Aiqun Liu ◽  
Zhuoran Tang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
T Cell ◽  
Carbon Quantum Dots ◽  
Sensitive Detection ◽  
Highly Sensitive ◽  
Highly Sensitive Detection ◽  
Fluorescent Carbon

Enhanced reduction of p-nitrophenol by zerovalent iron modified with carbon quantum dots

2021 ◽  
Vol 285 ◽  
pp. 119829
Author(s):  
Peng Fan ◽  
Xuanjun Zhang ◽  
Huanhuan Deng ◽  
Xiaohong Guan
Keyword(s):  
Quantum Dots ◽  
Carbon Quantum Dots ◽  
Zerovalent Iron

Synthesis of Fluorescent Nitrogen and Phosphorous Co-doped Carbon Quantum Dots for Sensing of Iron, Cell Imaging and Antioxidant Activities

2021 ◽  
Author(s):  
Aschalew Tadesse ◽  
Neway Belachew ◽  
Mebrahtu Hagos ◽  
Keloth Basavaiah
Keyword(s):  
Quantum Dots ◽  
Cell Imaging ◽  
Antioxidant Activities ◽  
Carbon Quantum Dots ◽  
Co Doped
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