Tailoring of graphene quantum dots for toxic heavy metals detection

2019 ◽  
Vol 125 (11) ◽  
Author(s):  
Hamid Reza Ghenaatian ◽  
Mehdi Shakourian-Fard ◽  
Masoud Rohani Moghadam ◽  
Ganesh Kamath ◽  
Mohsen Rahmanian
Keyword(s):  
Heavy Metals ◽  
Quantum Dots ◽  
Graphene Quantum Dots ◽  
Toxic Heavy Metals

scholarly journals On the interaction of toxic Heavy Metals (Cd, Hg, Pb) with graphene quantum dots and infinite graphene

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Ivan Shtepliuk ◽  
Nuala M. Caffrey ◽  
Tihomir Iakimov ◽  
Volodymyr Khranovskyy ◽  
Igor A. Abrikosov ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Quantum Dots ◽  
Graphene Quantum Dots ◽  
Toxic Heavy Metals

scholarly journals Interband transitions in closed-shell vacancy containing graphene quantum dots complexed with heavy metals

2018 ◽  
Vol 20 (33) ◽  
pp. 21528-21543 ◽  
Author(s):  
Ivan Shtepliuk ◽  
Rositsa Yakimova
Keyword(s):  
Heavy Metals ◽  
Quantum Dots ◽  
Strong Interaction ◽  
High Performance ◽  
Optical Detection ◽  
Graphene Quantum Dots ◽  
Closed Shell ◽  
Interband Transitions ◽  
Toxic Heavy Metals ◽  
Shell Vacancy

High-performance optical detection of toxic heavy metals by using graphene quantum dots (GQDs) requires a strong interaction between the metals and GQDs, which can be reached through artificial creation of vacancy-type defects in GQDs.

scholarly journals Insights into the origin of the excited transitions in graphene quantum dots interacting with heavy metals in different media

2017 ◽  
Vol 19 (45) ◽  
pp. 30445-30463 ◽  
Author(s):  
Ivan Shtepliuk ◽  
Volodymyr Khranovskyy ◽  
Rositsa Yakimova
Keyword(s):  
Heavy Metals ◽  
Quantum Dots ◽  
Electrochemical Sensors ◽  
Graphene Quantum Dots ◽  
Toxic Heavy Metals ◽  
Reliable Detection

Exploring graphene quantum dots (GQDs) is an attractive way to design novel optical and electrochemical sensors for fast and reliable detection of toxic heavy metals (HMs), such as Cd, Hg and Pb.

scholarly journals Detection of Heavy Metals in Water Using Graphene Oxide Quantum Dots: An Experimental and Theoretical Study

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5519
Author(s):  
Lorenzo Gontrani ◽  
Olivia Pulci ◽  
Marilena Carbone ◽  
Roberto Pizzoferrato ◽  
Paolo Prosposito
Keyword(s):  
Heavy Metals ◽  
Quantum Dots ◽  
Graphene Oxide ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Theoretical Study ◽  
Graphene Quantum Dots ◽  
Emission Spectra ◽  
Optical Response ◽  
Graphene Oxide Quantum Dots

In this work, we investigate by ab initio calculations and optical experiments the sensitivity of graphene quantum dots in their use as devices to measure the presence, and concentration, of heavy metals in water. We demonstrate that the quenching or enhancement in the optical response (absorption, emission) depends on the metallic ion considered. In particular, two cases of opposite behaviour are considered in detail: Cd2+, where we observe an increase in the emission optical response for increasing concentration, and Pb2+ whose emission spectra, vice versa, are quenched along the concentration rise. The experimental trends reported comply nicely with the different hydration patterns suggested by the models that are also capable of reproducing the minor quenching/enhancing effects observed in other ions. We envisage that quantum dots of graphene may be routinely used as cheap detectors to measure the degree of poisoning ions in water.

scholarly journals Detection of Heavy Metals in Water Using Graphene Quantum Dots: An Experimental and Theoretical Study

2021 ◽  
Author(s):  
Lorenzo Gontrani ◽  
Olivia Pulci ◽  
Marilena Carbone ◽  
Roberto Pizzoferrato ◽  
Paolo Prosposito
Keyword(s):  
Heavy Metals ◽  
Quantum Dots ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Theoretical Study ◽  
Graphene Quantum Dots ◽  
Emission Spectra ◽  
Optical Response ◽  
Test Cases

In this work, we investigate by ab initio calculations and optical experiments the sensitiv- ity of graphene quantum dots in their use as devices to measure the presence, and concentration, of heavy metals in water. We demonstrate that the quenching or enhancement in the optical response (absorption, emission) depends on the metallic ion considered. In particular, two test cases of opposite behaviour are considered: Cd 2+ , where we observe an increase in the optical response for increasing concentration, and Pb 2 whose emission spectra are quenched along the concentration rise. We envisage that quantum dots of graphene may be routinely used as cheap detectors to measure the degree of poisoning ions in water

First principles study of the adsorption of hydrated heavy metals on graphene quantum dots

2019 ◽  
Vol 130 ◽  
pp. 32-40 ◽  
Author(s):  
H. Abdelsalam ◽  
N.H. Teleb ◽  
I.S. Yahia ◽  
H.Y. Zahran ◽  
H. Elhaes ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Quantum Dots ◽  
First Principles ◽  
Graphene Quantum Dots ◽  
First Principles Study

scholarly journals Interband Absorption in Few-Layer Graphene Quantum Dots: Effect of Heavy Metals

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1217 ◽  
Author(s):  
Ivan Shtepliuk ◽  
Rositsa Yakimova
Keyword(s):  
Heavy Metals ◽  
Density Functional Theory ◽  
Quantum Dots ◽  
Density Functional ◽  
Colorimetric Detection ◽  
Graphene Quantum Dots ◽  
Metal Exposure ◽  
Partial Density ◽  
Interband Absorption ◽  
Functional Theory

Monolayer, bilayer, and trilayer graphene quantum dots (GQDs) with different binding abilities to elemental heavy metals (HMs: Cd, Hg, and Pb) were designed, and their electronic and optical properties were investigated theoretically to understand deeply the optical response under heavy metal exposure. To gain insight into the nature of interband absorption, we performed density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations for thickness-varying GQDs. We found that the interband absorption in GQDs can be efficiently tuned by controlling the thickness of GQDs to attain the desirable coloration of the interacting complex. We also show that the strength of the interaction between GQDs and Cd, Hg, and Pb is strongly dependent on the number of sp2-bonded layers. The results suggest that the thickness of GQDs plays an important role in governing the hybridization between locally-excited (LE) and charge-transfer (CT) states of the GQDs. Based on the partial density-of-states (DOS) analysis and in-depth knowledge of excited states, the mechanisms underlying the interband absorption are discussed. This study suggests that GQDs would show an improved sensing performance in the selective colorimetric detection of lead by the thickness control.

Preparation of Graphene Quantum Dots and Their Biological Applications

2016 ◽  
Vol 31 (4) ◽  
pp. 337 ◽  
Author(s):  
SUN Xiao-Dan ◽  
LIU Zhong-Qun ◽  
YAN Hao
Keyword(s):  
Quantum Dots ◽  
Graphene Quantum Dots ◽  
Biological Applications

ASSESSMENT OF HEAVY METAL CONCENTRATION IN COCONUT WATER

1970 ◽  
pp. 07-10
Author(s):  
MdDidarul Islam, Ashiqur Rahaman, Aboni Afrose
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Concentration ◽  
Coconut Water ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Toxic Heavy Metal ◽  
Low Concentration ◽  
Wet Ashing ◽  
Aas Method

This study was based on determining concentration of essential and toxic heavy metal in coconut water available at a local Hazaribagh area in Dhaka, Bangladesh. All essential minerals, if present in the drinking water at high concentration or very low concentration, it has negative actions. In this study, fifteen samples and eight heavy metals were analyzed by Atomic Absorption Spectroscopy (AAS) method which was followed by wet ashing digestion method. The concentration obtained in mg/l were in the range of 0.3 to 1.5, 7.77 to 21.2, 0 to 0.71, 0 to 0.9, 0 to 0.2, 0.9 to 17.3, 0.1 to 0.9, 0 to 0.9 and 0 to 0.7 for Fe, Ni, Cu, Cd, Cr, Zn, Pb and Se respectively. From this data it was concluded that any toxic heavy metals like Cd, Cr, Pb and Ni exceed their toxicity level and some essential nutrients were in low concentration in those samples. 

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