scholarly journals N-Doped Carbon Dots Derived from Melamine and Triethanolamine for Selective Sensing of Fe3+ Ions

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Sathishkumar Munusamy ◽  
Sathish Sawminathan ◽  
Thanigaivelan Arumugham ◽  
Maura Casales Díaz ◽  
Srinivas Godavarthi ◽  
...  
Keyword(s):  
Water Samples ◽  
Carbon Dots ◽  
Limit Of Detection ◽  
Blue Emission ◽  
World Health ◽  
Selective Determination ◽  
N Doping ◽  
Health Organization ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

This work reports nitrogen-doped carbon dots (NCDs) as a selective sensing probe to detect Fe3+ in water samples. NCD probes were synthesized via solvothermal method using nitrogen-rich melamine and triethanolamine as precursors. Properties of the resulting NCDs were studied using different characterization techniques, through which N-doping was confirmed. The quantum yield of obtained NCDs was measured to be 21%. When excited at 370 nm, the excellent blue emission property makes this probe adoptable for selectively sensing Fe3+ in practical water samples. The limit of detection (LOD) was identified as 216 nM with a good linear range between the concentrations of 0.2-2 μM. The obtained LOD is far less than the World Health Organization (WHO) permissible limits of Fe3+ in water. Interference studies reveal that the presence of other competing ions did not alter the sensing of Fe3+, even at the presence of 10 equivalents which indicates the high selectivity of NCDs towards Fe3+. The reversibility studies showed that adding a cheap and readily available EDTA ligand to the NCD results in fluorescence regeneration, leading to exceptional reusability for the detection of Fe3+. So, the synthesized NCDs can be used as a suitable probe for the selective determination of Fe3+ in real water samples.

Selective determination of Ag+ using Salecan derived nitrogen doped carbon dots as a fluorescent probe

2017 ◽  
Vol 77 ◽  
pp. 508-512 ◽  
Author(s):  
Junjian Li ◽  
Gancheng Zuo ◽  
Xiaoliang Qi ◽  
Wei Wei ◽  
Xiaohao Pan ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Carbon Dots ◽  
Selective Determination ◽  
Nitrogen Doped ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

scholarly journals Highly Photoluminescent and Stable N-Doped Carbon Dots as Nanoprobes for Hg2+ Detection

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 900 ◽  
Author(s):  
Longshi Rao ◽  
Yong Tang ◽  
Hanguang Lu ◽  
Shudong Yu ◽  
Xinrui Ding ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Dots ◽  
Limit Of Detection ◽  
Energy Levels ◽  
Orbital Energy ◽  
Synthesis Conditions ◽  
Porous Copper ◽  
Different Response ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

We developed a microreactor with porous copper fibers for synthesizing nitrogen-doped carbon dots (N-CDs) with a high stability and photoluminescence (PL) quantum yield (QY). By optimizing synthesis conditions, including the reaction temperature, flow rate, ethylenediamine dosage, and porosity of copper fibers, the N-CDs with a high PL QY of 73% were achieved. The PL QY of N-CDs was two times higher with copper fibers than without. The interrelations between the copper fibers with different porosities and the N-CDs were investigated using X-ray photoelectron spectroscopy (XPS) and Fourier Transform infrared spectroscopy (FTIR). The results demonstrate that the elemental contents and surface functional groups of N-CDs are significantly influenced by the porosity of copper fibers. The N-CDs can be used to effectively and selectively detect Hg2+ ions with a good linear response in the 0~50 μM Hg2+ ions concentration range, and the lowest limit of detection (LOD) is 2.54 nM, suggesting that the N-CDs have great potential for applications in the fields of environmental and hazard detection. Further studies reveal that the different d orbital energy levels of Hg2+ compared to those of other metal ions can affect the efficiency of electron transfer and thereby result in their different response in fluorescence quenching towards N-CDs.

scholarly journals Detection of Melamine Based on the Fluorescence Changes of Nitrogen-Doped Carbon Dots

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Wenzhi Yin ◽  
Chaoqun Ma ◽  
Tuo Zhu ◽  
Jiao Gu ◽  
Chun Zhu ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Detection Method ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Mercury Ions ◽  
Measuring Range ◽  
Nitrogen Doped ◽  
One Step ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

In order to determine the concentration of melamine, nitrogen-doped carbon dots (NCDs) were synthesized in one step as a fluorescent probe. Uric acid and diethylenetriamine were used as carbon source and nitrogen source, respectively. The experimental results showed that the fluorescence of NCDs can be quenched by mercury ions (Hg2+). Due to the strong coordination affinity between the carbon-nitrogen heterocyclic of melamine and Hg2+, part of Hg2+ coordinated with melamine when melamine was mixed with Hg2+. Then, the fluorescence of the added NCDs was quenched by the remaining Hg2+. Therefore, the concentration of melamine could be determined. The results show that the method has high sensitivity in wide measuring range that the linear ranges are 50–400 μg/L and 800–2500 μg/L, and the R2 is 0.997 and 0.988, respectively, with the limit of detection (LOD) of 21.76 μg/L. The NCDs are easy to fabricate, and the detection method is easy to implement. In this study, a new method for melamine detection was established, and the proposed method for melamine detection can provide some insights for food safety detection.

scholarly journals Green Hydrothermal Synthesis of N-doped Carbon Dots from Biomass Highland Barley for the Detection of Hg2+

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3169 ◽  
Author(s):  
Xie ◽  
Cheng ◽  
Liu ◽  
Han
Keyword(s):  
Carbon Dots ◽  
Limit Of Detection ◽  
Amorphous Structure ◽  
Water Soluble ◽  
Diameter Distribution ◽  
High Quantum Yield ◽  
N Doping ◽  
Ft Ir ◽  
Doped Carbon Dots ◽  
Highland Barley

Totally water-soluble N-doped Carbon dots (N-CDs) were synthesized by a green hydrothermal method from biomass using Highland barley as a carbon source and ethanediamine as nitrogen source. TEM and XRD showed the graphitic amorphous structure and narrow diameter distribution of these N-CDs. N-doping to the crystal lattice and carrying many hydrophilic groups on the surface of N-CDs were verified by XPS and FT-IR. The as-synthesized N-CDs emitted strong blue fluorescence at 480 nm and owned a relatively high quantum yield of 14.4%. The product also could sensitively and selectively detect Hg2+ ions in the range of 10–160 μM and the limit of detection was equal to 0.48 μM.

scholarly journals A Chelation-Enhanced Fluorescence Assay Using Thiourea Capped Carbonaceous Fluorescent Nanoparticles For As (III) Detection In Water Samples

2021 ◽  
Author(s):  
Susan Mohammadi ◽  
Somayeh Mohammadi ◽  
Abdollah Salimi ◽  
Rezgar Ahmadi
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Threshold Value ◽  
Water Soluble ◽  
World Health ◽  
Fluorescent Nanoparticles ◽  
Detection Range ◽  
Turn On ◽  
Efficient Detection ◽  
Health Organization

Abstract Herein, we designed a sensitive and selective “Turn-On” fluorescence nanosensor using water-soluble carbonaceous fluorescent nanomaterials (CFNs) functionalized with thiourea (CFNs-thiourea) for efficient detection of trace amounts of arsenic (III) in aqueous samples. The CFNs and CFNs-Thiourea were characterized by transmission electron microscopy (TEM), UV–Visible spectroscopy (UV-vis) and Fourier transformed infrared spectroscopy (FTIR). The emission peak intensity of proposed nanosensor at 425 nm was gradually enhanced on arsenite addition in wide detection range (3.3–828.5 µg L-1) attributed to the binding of arsenite species with sulfur groups of CFNs-thiourea. The limit of detection (LOD) was 0.48 µg L-1 being much lower than the World Health Organization (WHO) recommended threshold value of 10 µg L-1. Furthermore, the as prepared thiourea -CFNs exhibited an superb selectivity for As (III) compared various cations and anions such as; NO3−, NO2−, F−, Ni2+, Fe3+, Cu2+, Ca2+, Mg2+, Zn2+, Fe2+, Hg2+, Pb2+, F-, Cl-, Mn2+, Cr3+, Co2+, Cd2+, Bi3+, Al3+ and As (V) at 100 folds concentration of As (III). The turn on fluorescence nanosensor was successfully exploited for quantification of arsenic in spiked water samples with acceptable efficiencies.

Selective determination of free dissolved chlorine using nitrogen-doped carbon dots as a fluorescent probe

2016 ◽  
Vol 183 (7) ◽  
pp. 2221-2227 ◽  
Author(s):  
Yanping Lin ◽  
Bixia Yao ◽  
Tingting Huang ◽  
Shichao Zhang ◽  
Xiaotong Cao ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Carbon Dots ◽  
Selective Determination ◽  
Nitrogen Doped ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

Highly Photoluminescent Carbon Dots with pH-Dependent Switchable Fluorescence and Sensitivity to Tetracycline

NANO ◽  
2021 ◽  
pp. 2150036
Author(s):  
Chengwei Wang ◽  
Lei Li ◽  
Yamin Wu ◽  
Jiao Gu ◽  
Chaoqun Ma ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Water Solubility ◽  
Ph Value ◽  
Limit Of Detection ◽  
Temperature Stability ◽  
High Quantum Yield ◽  
Light Stability ◽  
One Step ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

In this paper, multifunctional nitrogen-doped carbon dots (N-CDs) were synthesized from 3,5-diaminobenzonitrile by a simple one-step hydrothermal method. The N-CDs have a high quantum yield of 67.0% in ethanol with great water solubility, temperature stability, light stability and resistance to ion interference. Experiments showed that pH has an effect on the fluorescence intensity and emission wavelength of N-CDs. Especially, the switchable fluorescence of N-CDs caused by changes of pH value could be distinguished to the naked eye. Additionally, the multifunctional N-CDs also showed a selective response to tetracycline. We studied the influence of tetracycline on the luminescence intensity of N-CDs in the concentration range of 0–1000[Formula: see text][Formula: see text]g/L. A linear equation was established in the range of 10–80[Formula: see text][Formula: see text]g/L with a limit of detection (LOD) of 3.5[Formula: see text][Formula: see text]g/L. Based on the above excellent characteristics, N-CDs are expected to be applied in the field of sensing.

Fluorescent Nitrogen-Doped Carbon Dots via Single-Step Synthesis Applied as Fluorescent Probe for the Detection of Fe3+ Ions and Anti-Counterfeiting Inks

NANO ◽  
2018 ◽  
Vol 13 (08) ◽  
pp. 1850097 ◽  
Author(s):  
Chonghui Fan ◽  
Kelong Ao ◽  
Pengfei Lv ◽  
Jiancheng Dong ◽  
Di Wang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Dots ◽  
Water Solubility ◽  
Fluorescence Probe ◽  
Limit Of Detection ◽  
Single Step ◽  
Nitrogen Doped ◽  
Ambient Lighting ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

Fluorescent nitrogen-doped carbon dots (N-CDs) with excellent stability were prepared via single-step hydrothermal carbonization of citric acid (CA) and ethylenediamine (EDA). The as-prepared N-CDs emit blue fluorescence under the excitation of 365[Formula: see text]nm and have a size distribution of 2.80 ± 0.47[Formula: see text]nm with benign size effect. The structure and morphology were further characterized by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. It was found that the surface of the N-CDs was successfully functionalized, which presented water solubility and chelation with Fe3+. XRD results display a diffraction peak at 23.9°C, which corresponds to the (002) interlayer spacing of a graphitic structure revealing an amorphous carbon phase. Furthermore, due to good sensitivity, N-CDs were used as probes for Fe3+ detection. The low limit of detection of 0.6[Formula: see text]μM as a fluorescence probe was successfully obtained based on the linear relationship between ([Formula: see text] and concentration of Fe3+ ions. Besides the satisfactory fluorescence, PVA/N-CDs membranes and fluorescent inks demonstrate potential for anti-counterfeiting applications due to its characteristic flexibility, transparency, removability and invisibility under ambient lighting.

Sign in / Sign up

Export Citation Format

Share Document