scholarly journals Development of Graphene Quantum Dots-Based Optical Sensor for Toxic Metal Ion Detection

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3850 ◽  
Author(s):  
Nur Ain Asyiqin Anas ◽  
Yap Wing Fen ◽  
Nur Alia Sheh Omar ◽  
Wan Mohd Ebtisyam Mustaqim Mohd Daniyal ◽  
Nur Syahira Md Ramdzan ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Metal Ions ◽  
Optical Sensors ◽  
Metal Ion ◽  
Limit Of Detection ◽  
Graphene Quantum Dots ◽  
Toxic Metal ◽  
Human Beings ◽  
Toxic Metal Ions ◽  
Sensing Applications

About 71% of the Earth’s surface is covered with water. Human beings, animals, and plants need water in order to survive. Therefore, it is one of the most important substances that exist on Earth. However, most of the water resources nowadays are insufficiently clean, since they are contaminated with toxic metal ions due to the improper disposal of pollutants into water through industrial and agricultural activities. These toxic metal ions need to be detected as fast as possible so that the situation will not become more critical and cause more harm in the future. Since then, numerous sensing methods have been proposed, including chemical and optical sensors that aim to detect these toxic metal ions. All of the researchers compete with each other to build sensors with the lowest limit of detection and high sensitivity and selectivity. Graphene quantum dots (GQDs) have emerged as a highly potential sensing material to incorporate with the developed sensors due to the advantages of GQDs. Several recent studies showed that GQDs, functionalized GQDs, and their composites were able to enhance the optical detection of metal ions. The aim of this paper is to review the existing, latest, and updated studies on optical sensing applications of GQDs-based materials toward toxic metal ions and future developments of an excellent GQDs-based SPR sensor as an alternative toxic metal ion sensor.

Red-fluorescent graphene quantum dots from guava leaf as a turn-off probe for sensing aqueous Hg(ii)

2021 ◽  
Vol 45 (10) ◽  
pp. 4617-4625
Author(s):  
Rahul V. Khose ◽  
Goutam Chakraborty ◽  
Mahesh P. Bondarde ◽  
Pravin H. Wadekar ◽  
Alok K. Ray ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Metal Ion ◽  
Leaf Extract ◽  
Graphene Quantum Dots ◽  
Toxic Metal ◽  
Guava Leaf

In this work, we have prepared red-fluorescent graphene quantum dots and utilized as a highly selective and sensitive fluorescence turn-off probe for detection of the toxic metal ion Hg2+ from guava leaf extract.

Optical Sensors Based on Nanostructured Cage Materials for the Detection of Toxic Metal Ions

2006 ◽  
Vol 45 (43) ◽  
pp. 7202-7208 ◽  
Author(s):  
Tatineni Balaji ◽  
Sherif A. El-Safty ◽  
Hideyuki Matsunaga ◽  
Takaaki Hanaoka ◽  
Fujio Mizukami
Keyword(s):  
Metal Ions ◽  
Optical Sensors ◽  
Toxic Metal ◽  
Toxic Metal Ions

A Portable Analytical System for Colorimetric Detection of Metal Ions in Water

2014 ◽  
Author(s):  
Chen Zhao ◽  
Guowei Zhong ◽  
Da-Eun Kim ◽  
Jinxia Liu ◽  
Xinyu Liu
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Limit Of Detection ◽  
Colorimetric Detection ◽  
Colorimetric Method ◽  
Human Beings ◽  
Aluminum Ions ◽  
Analytical System

Heavy metal ions released into various water environments have severe impact on both human beings and aqueous environments, and excess amount of lead and aluminum ions pose high risks to human health and could cause life-threatened diseases. The existence of metal ions in drinking water contributes most to the daily intake by humans, and thus it urges to develop a rapid, low-cost and sensitive method for detection of heavy metal ions. In this research, we develop a portable analytical system for metal ion detection in water by combining a powerful gold nanoparticle (AuNP) based colorimetric method with lab-on-a-chip technology. We utilize single-step assays involving surface functionalized AuNPs for colorimetric detection of lead (Pb2+) and aluminum (Al3+) ions in water with low limit of detection (LOD) and high sensitivity. We demonstrate that this portable system provides LODs of 30 ppb for Pb2+ and 89 ppb for Al3+, both comparable to bench-top analytical spectrometers. The system permits metal ion detections in a more economical and convenient fashion, and is particularly useful for water quality monitoring in remote and/or resource-poor settings.

Toxic metal ions in water and their prevalence in Uttarakhand, India

2012 ◽  
Vol 12 (6) ◽  
pp. 773-782 ◽  
Author(s):  
Vinod Kumar Gupta ◽  
Rajendra Dobhal ◽  
Arunima Nayak ◽  
Shilpi Agarwal ◽  
Devi Prasad Uniyal ◽  
...  
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Toxic Metal ◽  
Industrial Wastes ◽  
World Health ◽  
Toxic Metal Ions ◽  
Set Up ◽  
Health Organization ◽  
Almost All

Developmental activities, geological reasons and mixing of industrial wastes are responsible for the deteriorating quality of surface and ground water in the Himalayan state of Uttarakhand. The drinking water sources of 13 districts of Uttarakhand have been assessed for the presence of four toxic metal ions (arsenic, cadmium, chromium and lead). The health aspects of the four metal ions have also been reviewed according to the prescribed limits set up by the Bureau of Indian Standards (BIS) and World Health Organization (WHO). The present study reveals the absence of arsenic at almost all stations. Cadmium has been found only at Rudrapur, whereas chromium is found to be present in more than prescribed limits, in Kolti, Mussoorie and Dehradun. Significant presence of lead in the six districts of the state is indicative of the fact that proper management strategy of toxic metal ion remediation is required. Chromium and lead have exceeded the prescribed limit in 1.3 and 4.5% samples, respectively. However, as per BIS standard, cadmium is higher than the prescribed limit in 0.6% samples but according to the WHO standard, cadmium has exceeded in about 26% samples. Out of the total 156 samples analyzed, 6.4 and 33.3% samples have been found to possess the toxic metal ions in more than the prescribed limits as per BIS and WHO guidelines, respectively.

Graphene Quantum Dots Electrochemistry and Development of Ultrasensitive Enzymatic Glucose Sensor

MRS Advances ◽  
2018 ◽  
Vol 3 (15-16) ◽  
pp. 831-847 ◽  
Author(s):  
Sanju Gupta ◽  
Tyler Smith ◽  
Alexander Banaszak ◽  
John Boeckl
Keyword(s):  
Quantum Dots ◽  
Electron Transfer ◽  
Cyclic Voltammetry ◽  
Glucose Sensor ◽  
Limit Of Detection ◽  
Direct Electron Transfer ◽  
Graphene Quantum Dots ◽  
Optimal Size ◽  
Sensing Applications ◽  
Edge Site

AbstractGraphene quantum dots (GQDs) - zero-dimensional materials - are sheets of a few nanometers in lateral dimension and exhibit quantum confinement and edge site effects where sp2-bonded carbon nanocore surrounded with edged plane functional moieties is promising as advanced electroactive sensing platforms. In this work, GQDs are synthesized by solvothermal and hydrothermal techniques, with optimal size of 5 nm. Their potential in fundamental (direct electron transfer) and applied (enzymatic glucose biosensor) electrochemistry are demonstrated. Glucose oxidase (GOx) immobilized on glassy carbon (GC) electrodes modified with GQDs are investigated by means of cyclic voltammetry, differential pulse voltammetry, and amperometry. Well-defined quasi-reversible redox peaks observed under various electrochemical parameters helped to determine diffusion coefficient (D) and first-order electron transfer rate (kET). The cyclic voltammetry curves showed homogeneous ion transport for GQD with D ranging between 8.45 × 10−9 m2 s−1 and 3 × 10−8 m2 s−1 following GO < rGO < GQD < GQD (with FcMeOH as redox probe) < GOx/rGO < GOx/GO < HRP/GQDs < GOx/GQDs. The developed GOx-GQDs biosensor responds efficiently and linearly to the presence of glucose over concentrations ranging 10 μM and 3 mM with limit of detection 1.35 μM and sensitivity 0.00769 μA μM−1·cm−2 as compared with rGO (0.025 μA μM−1 cm−2, 4.16 μM) and GO (0.064 μA μM−1 cm−2, 4.82 μM) nanosheets. The high performance and stability of GQDs is attributed to sufficiently large surface-to-volume ratio, excellent biocompatibility, abundant hydrophilic edge site density, and partially hydrophobic planar sites that favors GOx adsorption on the electrode surface and versatile architectures to ensure rapid charge transfer and electron/ion conduction (<10 ms). We also carried out similar studies with other enzymatic protein biomolecules on electrode surfaces prepared from GQD precursors for electrochemical comparison, thus opening up potential sensing applications in medicine as well as bio-nanotechnology.

Optical Sensors Based on Nanostructured Cage Materials for the Detection of Toxic Metal Ions

2006 ◽  
Vol 118 (43) ◽  
pp. 7360-7366 ◽  
Author(s):  
Tatineni Balaji ◽  
Sherif A. El-Safty ◽  
Hideyuki Matsunaga ◽  
Takaaki Hanaoka ◽  
Fujio Mizukami
Keyword(s):  
Metal Ions ◽  
Optical Sensors ◽  
Toxic Metal ◽  
Toxic Metal Ions

Glutathione Capped CdSe Quantum Dots: Synthesis, Characterization, Morphology, and Application as a Sensor for Toxic Metal Ions

2019 ◽  
Vol 19 (2) ◽  
pp. 1192-1195 ◽  
Author(s):  
Long Giang Bach ◽  
Trinh Duy Nguyen ◽  
Nguyen Thi Thuong ◽  
Ho Thi Thanh Van ◽  
Kwon Taek Lim
Keyword(s):  
Quantum Dots ◽  
Metal Ions ◽  
Toxic Metal ◽  
Cdse Quantum Dots ◽  
Toxic Metal Ions

Nano platelets kaolinite for the adsorption of toxic metal ions in the environment

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Low Cost ◽  
Toxic Metal ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Toxic Heavy Metals ◽  
Toxic Metal Ions ◽  
Endothermic Process ◽  
Langmuir Isotherm Model

Contamination of water reservoirs with different toxic metal ions from industrial activities has emerged as one of major issues in recent years. The adsorption of Pb(II) ions from aqueous solution onto Nano platelets kaolinite has been investigated. The adsorption studies were determined as a function of pH, contact time, initial metal ion concentration, adsorbent dosage and temperature. Nano platelets kaolinite prepared from raw Jordanian kaolin clay showed size in the range of 12-80 nm. Maximum adsorption capacity as determined by Langmuir isotherm model is 175.44 mg/g for Pb(II). Thermodynamic parameters, ΔGo, ΔHo and ΔSo were revealed that the adsorption process is spontaneous and endothermic process. The results showed that Nano platelets kaolinite can be efficiently used as a low-cost alternative and eco-friendly adsorbent for the removal of toxic heavy metals from wastewater.

scholarly journals Binary Adsorption Studies of Toxic Metal Ions of Lead and Copper from Aqueous Solution by Modified Foeniculum vulgaris Seeds (Fennel Seeds)

2021 ◽  
Vol 33 (7) ◽  
pp. 1611-1619
Author(s):  
Ntandokazi Mabungela ◽  
Ntaote David Shooto ◽  
Fanyana Mtunzi ◽  
Eliazer Bobby Naidoo
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
Toxic Metal ◽  
Maximum Adsorption Capacity ◽  
Human Beings ◽  
Binary Adsorption ◽  
Aquatic Life ◽  
Initial Concentration ◽  
Toxic Metal Ions ◽  
Acid And Base

Discharge of copper(II) and lead(II) ions into rivers and streams by industries and other human activities has gained serious consideration from regulatory bodies. These toxic metals are harmful to human beings and aquatic life when in high concentrations. Therefore, their removal from wastewater is very important. Hence, this work reports the binary adsorption of toxic metal ions of Cu(II) and Pb(II) from aqueous solution by pristine and modified fennel seeds. Pristine fennel seeds (PFS) were treated with acidic and alkaline solutions to develop modified adsorbents designated ATFS and BTFS, respectively. SEM images revealed that PFS had an amorphous surface with irregular cavities. However, upon acid and base treatment, the surface was more refined. The ATFS had interconnected pores while BTFS had somewhat honeycomb pores. The UV-Vis results confirmed that some of the components were removed from PFS during acid and base pre-treatment. FTIR spectra revealed that the adsorbents had functional groups such as (-OH) and (-C=O), which were involved in the uptake of the metal ions. It was observed that the uptake of Cu(II) and Pb(II) ions onto all adsorbents progressively increased when the initial concentration of the solution was increased. The maximum adsorption capacity was obtained when the initial concentration of the solution was 100 mg/L. The uptake of Cu(II) and Pb(II) on PFS was 3.345 and 11.524 mg/g. While for ATFS 3.78 and 13.07 mg/g and BTFS 8.143 and 14.85 mg/g, respectively. It was observed that the isotherm data fitted Freundlich better for the uptake of both metal ions onto all adsorbents. It was observed that there was a rapid uptake when contact time increased from 5 to 60 min. However, when time increased above 60 min the uptake stabilized and reached equilibrium this was due to the saturation of active sites on the surface for all adsorbents. The kinetics study revealed that PSO fitted the data better than PFO. IPD data revealed that the uptake of metal ions was controlled by the synergistic of ESA and EPA. The ΔHº values for Cu(II) and Pb(II) uptake onto all adsorbents were all negative. This suggested that the reactions were exothermic.

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