scholarly journals Oil-Dispersible Green-Emitting Carbon Dots: New Insights on a Facile and Efficient Synthesis

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3716
Author(s):  
Gianluca Minervini ◽  
Annamaria Panniello ◽  
Elisabetta Fanizza ◽  
Angela Agostiano ◽  
Maria Lucia Curri ◽  
...  

Carbon dots (CDs) have been progressively attracting interest as novel environmentally friendly and cost-effective luminescent nanoparticles, for implementation in light-emitting devices, solar cells, photocatalytic devices and biosensors. Here, starting from a cost-effective bottom-up synthetic approach, based on a suitable amphiphilic molecule as carbon precursor, namely cetylpyridinium chloride (CPC), green-emitting CDs have been prepared at room temperature, upon treatment of CPC with concentrated NaOH solutions. The investigated method allows the obtaining, in one-pot, of both water-dispersible (W-CDs) and oil-dispersible green-emitting CDs (O-CDs). The study provides original insights into the chemical reactions involved in the process of the carbonization of CPC, proposing a reliable mechanism for the formation of the O-CDs in an aqueous system. The ability to discriminate the contribution of different species, including molecular fluorophores, allows one to properly single out the O-CDs emission. In addition, a mild heating of the reaction mixture, at 70 °C, has demonstrated the ability to dramatically decrease the very long reaction time (i.e. from tens of hours to days) at room temperature, allowing us to synthesize O-CDs in a few tens of minutes while preserving their morphological and optical properties.

2021 ◽  
Author(s):  
Wenbing Cao ◽  
Yuhan Wu ◽  
Xin Li ◽  
Xuanfeng Jiang ◽  
Yuhong Zhang ◽  
...  

Abstract Silane-functionalized carbon dots (SiCDs) can be exploited as effective color converting materials for the solid-state light-emitting devices. However, most of SiCDs reported thus far have shown photoluminescence emissions in the blue and green spectral range, which limit them to construct an efficient white light-emitting diodes (WLEDs) due to the lack of long-wavelength emission. Herein, a series of double silane-functionalized carbon dots (DSiCDs) were prepared via a one-step solvothermal method. The results show that the organic functional group of the silane has great influence on the optical properties of DSiCDs and the number of alkoxy group in the silane has great influence on coating properties of DSiCDs. In addition, the DSiCDs prepared by (3-aminopropyl)triethoxysilane and N-[3-(Trimethoxysilyl)propyl]ethylenediamine with molar ratio of 7:3 show excellent optical properties with the maximum emission at 608 nm under 400 nm excitation. Furthermore, they can be completely dried within 1 h at room temperature to form fluorescent coating with high stability and strong adhesion to the substrate. Together with their excellent optical and coating properties, they can be directly coated on LED chips to prepare WLEDs, with a CIE coordinate of (0.33,0.31), color rendering index of 81.6, and color temperature of 5774 K.


Author(s):  
Ali Ghafarloo ◽  
Reza Sabzi ◽  
Naser Samadi ◽  
Hamed Hamishehkar

Synthesis of carbon dots (CDs) from natural resources not only enables green synthesis and production of environmentally friendly materials, but also provides a cost-effective probe as a fluorescence nanosensor. The proposed sensor introduces a unique one-pot hydrothermal CDs synthesis from alfalfa leaves, which is promising for sensing hydrochlorothiazide (HCTZ) via inner filter effect (IFE) and resonance Rayleigh scattering (RRS). The as-prepared CDs had wide emission spectra, excitation-dependent emission, high solubility, high stability, and visible fluorescence light with a quantum yield of up to 11%. The absorption of HCTZ overlapped with the excitation spectra of CDs. Therefore, CDs represented excellent quenching due to IFE when HCTZ was gradually added. Furthermore, this fluorescent sensor was successfully used to quantify HCTZ in the linear ranges (0.17-2.50 μg mL-1) with the limit of detection of 0.11 μg mL-1. The sensing system was simple as no surface functionalization was required for CDs, leading to less laborious steps and more cost-effective synthesis. The reaction time was short, i.e., less than 2 min, indicating a simple approach for rapid analysis of HCTZ. By optimizing conditions, successful measurements were carried out on pharmaceutical tablets.


2008 ◽  
Vol 1138 ◽  
Author(s):  
Oluwatobi S. Oluwafemi ◽  
Neerish Revaprasadu

AbstractWe herein report a facile, ‘green’ one- step synthesis of a series of monodispersed water-soluble selenide nanoparticles at room temperature. The capping ligands used include, cysteine, methionine, ascorbic acid and starch which function as agents of solubilisation, stabilization and conjugation sites for biomolecules. The synthetic approach involves the addition of an appropriate volume of selenide ion produced via the reduction of selenium powder in water to an aqueous solution containing the ligand- metal salt (MCl2 M = Zn or Cd). Optical spectroscopy shows that the particles are of high quality while the transmission electron microscopy (TEM) of the samples shows variation in shapes ranging from dots to rods of high and low aspect ratios.


2015 ◽  
Vol 7 (6) ◽  
pp. 473-479
Author(s):  
P. S. Karthik ◽  
A. L. Himaja ◽  
Surya Prakash Singh

RSC Advances ◽  
2015 ◽  
Vol 5 (15) ◽  
pp. 11667-11675 ◽  
Author(s):  
Baozhan Zheng ◽  
Tao Liu ◽  
Man Chin Paau ◽  
Meina Wang ◽  
Yang Liu ◽  
...  

This work reports a simple and energy-saving strategy for selective synthesis of water-soluble and organic-soluble carbon dots at room temperature.


2016 ◽  
Vol 4 (41) ◽  
pp. 15880-15887 ◽  
Author(s):  
Longhua Xu ◽  
Guozhen Fang ◽  
Jifeng Liu ◽  
Mingfei Pan ◽  
Ranran Wang ◽  
...  

One-pot synthesis of nanoscale carbon dot-embedded metal–organic frameworks for enhanced chemical sensing.


RSC Advances ◽  
2014 ◽  
Vol 4 (43) ◽  
pp. 22318-22323 ◽  
Author(s):  
Xiao Yan ◽  
Jin-Long Chen ◽  
Meng-Xiang Su ◽  
Fang Yan ◽  
Bo Li ◽  
...  

Room temperature phosphorescence of carbon dots readily engineered by ferric ions in aqueous solution was developed for a novel “off-to-on” approach for cost-effective estimation of ATP level in human blood plasma.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Alexandra A. P. Mansur ◽  
Herman S. Mansur ◽  
Sandhra M. Carvalho ◽  
Anderson J. Caires

Cancer research has experienced astonishing advances recently, but cancer remains a major threat because it is one of the leading causes of death worldwide. Glioblastoma (GBM) is the most malignant brain tumor, where the early diagnosis is vital for longer survival. Thus, this study reports the synthesis of novel water-dispersible ternary AgInS2 (AIS) and quaternary AgInS2-ZnS (ZAIS) fluorescent quantum dots using carboxymethylcellulose (CMC) as ligand for multiplexed bioimaging of malignant glioma cells (U-87 MG). Firstly, AgInS2 core was prepared using a one-pot aqueous synthesis stabilized by CMC at room temperature and physiological pH. Then, an outer layer of ZnS was grown and thermally annealed to improve their optical properties and split the emission range, leading to core-shell alloyed nanostructures. Their physicochemical and optical properties were characterized, demonstrating that luminescent monodispersed AIS and ZAIS QDs were produced with average sizes of 2.2 nm and 4.3 nm, respectively. Moreover, the results evidenced that they were cytocompatible using in vitro cell viability assays towards human embryonic kidney cell line (HEK 293T) and U-87 MG cells. These AIS and ZAIS successfully behaved as fluorescent nanoprobes (red and green, resp.) allowing multiplexed bioimaging and biolabeling of costained glioma cells using confocal microscopy.


Sign in / Sign up

Export Citation Format

Share Document