China 
Africa 
Explore chapters and articles related to this topic
Metal-Organic Frameworks for Organic Dye AdsorptionsStrategic Design and Interaction Aspects
Published in Ram K. Gupta, Tahir Rasheed, Tuan Anh Nguyen, Muhammad Bilal, Metal-Organic Frameworks-Based Hybrid Materials for Environmental Sensing and Monitoring, 2022
Nabakrushna Behera, Sumit Mohapatra, Tankadhar Behera, Sipun Sethi
Generally, MOF-dye adsorption only based on acid-base interactions is hardly seen. However, a cobalt-based 3D-supramolecular MOF constructed from mixed ligand systems has been reported to have selective adsorption for orange IV (OIV) and MO dyes through Lewis acid-base interactions [40]. In the interaction process, the cobalt ions (Lewis acid) as open active sites can coordinate with the sulfonate salt (Lewis base) contained in OIV/MO. Proper functionalization of the MOF can lead to establishing such interactions with the dye molecules. As an example, the functionalization of the MIL-100(Fe) MOF has been achieved with thioglycolic acid, which has resulted in a fresh thiol-functionalized analog material (TH-MIL-100) for efficient removal of eosin B dyes [41]. The effective adsorption of eosin B dyes by TH-MIL-100 has been attributed to the acid-base interaction between the acidic thiol group (–SH) and the alkaline medium of eosin B dye solution. Recently, with the help of Fe3+ (hard acid), Ahamad et al. have modified the surface properties of the Cu- and Ni-based MOFs containing free carboxylic acid groups [42]. The oxygen (hard base) of the carboxylate group binds Fe3+ strongly and generates many unsaturated coordination sites in the MOF. These post synthetically modified MOFs, due to Fe3+ ions, effectively adsorb MB and MO molecules more effective in comparison to the parent MOFs. The unsaturated metal sites easily interact with the hard donors of the dyes (N and/or O) in accordance with the hard-soft acid-base (HSAB) principle (Figure 19.15) [42].
Phosphors in Role of Magnetic Resonance, Medical Imaging and Drug Delivery Applications: A Review
Published in Vikas Dubey, Sudipta Som, Vijay Kumar, Luminescent Materials in Display and Biomedical Applications, 2020
Neha Dubey, Vikas Dubey, Jagjeet Kaur, Dhananjay Kumar Deshmukh, K.V.R. Murthy
Drug Carrier for Photo-thermal Therapy: The design of upconversion nanocomposites for photo-thermal therapy is based on an agent that absorbs excitation radiation and transfers it to heat energy. Because of the low absorption ability of UCNPs, nanocomposites can possess the photo-thermal therapy effect only by introducing an additional component with high absorption efficiency at the excitation wavelength, otherwise the UCNP can only act as an upconversion indicator. Au and Ag nanoparticles, with strong extinction bands originating from the surface plasmon, can be introduced as a photo-thermal therapy agent. Song et al. have designed and synthesized a core-shell NaYF4:Yb,Er@Ag nanocomposite for UCL imaging and therapeutic applications (Dong et al. 2011). Thioglycolic acid (TGA) was chosen as the link to coordinate on the surface of UCNPs, and its thiol group performs as the active site during the formation of Ag nanocrystals. The Ag shell has the ability to transfer the incident 808 nm radiation to heat energy, and such light-to-heat conversion could be used to kill cancer cells effectively. Liu et al. incorporated Au nanoparticles onto the surface of UCNPs with the assistance of an intermediate layer composed of iron oxide (Cheng et al. 2012).
Biosynthesis of CdSe Nanoparticles by Anaerobic Granular Sludge
Published in Joyabrata Mal, Microbial Synthesis of Chalcogenide Nanoparticles, 2018
The Cd ions might interact with the sulfhydryl (-SH) group mainly present in the EPS originating from anaerobic granular sludge biofilm, leading to the formation of a CdS shell structure around a CdSe core. A similar interaction between Cd(II) and -SH occurred during the biosynthesis of CdS NPs using EPS extracted from Pseudomonas aeruginosa (Raj et al., 2016). Mak et al. (2011) reported that when CdTe QDs were capped with different capping agents like 3-mercaptopropionic acid, thioglycolic acid or thioglycerol thiol groups, a similar interaction between the -SH group of the capping agent and the core of the QDs and formation of CdSxTe1-x was observed. The absence of a proper CdS LO phonon peak in the supernatant sample (Fig. 5.6) was probably due to the partial alloying with the core (Dzhagan et al., 2013).
Photodegradation of crystal violet dye in water using octadecylamine-capped CdS nanoparticles synthesized from Cd(II) N,N′-diarylformamidine dithiocarbamates and their 2,2-bipyridine adducts
Published in Journal of Coordination Chemistry, 2022
Segun D. Oladipo, Bernard Omondi
The photocatalytic activity of the synthesized CdS nanoparticles was evaluated using crystal violet dye under visible light irradiation. Figure 8a–c shows the absorption spectrum of the dye at different time intervals. The decolorization of crystal violet is indicated by the decrease in absorption intensity as indicated in the spectrum, which confirms the destruction of the chromophore responsible for absorption. An almost complete degradation was observed after 360 min of irradiation time at 84.4%, 81.1% and 75.23% for CdS1, CdS3, and CdS5 (Figure 8d). CdS5 has a lower degradation efficiency; this could be due to short transportation length during immigration of electron-hole recombination because of large particle size and hence they cannot participate in the reaction process [32]. The degradation efficiencies of the as-synthesized ODA-capped CdS nanoparticles were compared to the ones previously reported. The use of uncapped CdS nanoparticles as a photocatalyst (0.25 g) in the degradation of crystal violet gave 43.27% efficiency for 180 min as reported by Upadhyay et al. [60] while thioglycolic acid-capped CdS, potassium pyrosulphate-capped CdS and disodium salt of EDTA-capped CdS (0.1 g for each) gave 96%, 95% and 76% degradation efficiency for 105 min as reported by Prasad et al. [61].
Fluorescent determination of trinitrotoluene with bovine serum albumin mediated enhancement of thioglycolic acid capped cadmium selenium quantum dots
Published in Instrumentation Science & Technology, 2018
These measurements show that the photoluminescence emission intensity of thioglycolic acid capped CdSe quantum dots increases with pH from 4 to 12. The major contribution may be from the pKa values of the carboxylic acid groups of this stabilizing ligand and the net amount of ligand present in the quantum dot solution.[29] This pH-dependent variation of photoluminescence emission of thioglycolic acid capped CdSe quantum dots may be explained because the carboxylic acid groups of thioglycolic acid (pKaCOOH 3.6) is highly negative at higher pH. This phenomenon results in the increased stabilization of these quantum dots. This observation of pH-dependent photoluminescence emission is in agreement with other reported studies on CdSe and CdTe quantum dots stabilized with thiolate ligands.[30,31] The photograph of these quantum dots solutions at various pH values under ultraviolet-illumination shows the increased emission and confirms the above result (inset of Figure 4b).
Recent advances on fluorescent biomarkers of near-infrared quantum dots for in vitro and in vivo imaging
Published in Science and Technology of Advanced Materials, 2019
Shanmugavel Chinnathambi, Naoto Shirahata
CdTe and HgTe QDs are most widely used in the NIR region. Gao et al. developed CdTexSe1– x/ZnS alloy nanocrystals to achieve QYs up to 80% with controllable rod-shape and NIR (λem = 650–870 nm) emission (Figure 2(a)) [21]. He et al. reported a facile one-step microwave synthesis of water-soluble CdTe QDs. The water-soluble NIR CdTe QDs (λem = 700–800 nm) are used first time for in vivo tumor targeting and also used for in vitro imaging after conjugation with protein molecules (Figure 2(b,d,f)) [22]. Recently, Geiregat et al. demonstrated that mercury telluride (HgTe) QDs exhibit size-tunable emission all over the NIR window at thresholds unmatched by any QDs studied before (Figure 2(c)) [23]. Alloyed CdTe1−xSex/CdS NIR QDs are used for detecting pancreatic cancer in mouse models [24]. Alloyed CdHgTe QDs were prepared via heating a mixture of Cd2+, Hg2+, and Te2- in the presence of 3-mercaptopropionic acid (MPA) as ligands with photoluminescence (PL) QYs (20–50%) and narrow emission bands and it will be a suitable fluorescent probe in the imaging of living animals [25]. Recently, Liu et al. developed a NIR-emitting CdHgTe/CdS/CdZnS QDs and coated them with three different thiol ligands, 3-MPA, thioglycolic acid (TGA), and N-acetyl-L-cysteine (NAC). In vivo toxicity measurement shows negligible harmful effects to nude mice even at a concentration of 20 mg kg−1 [26]. Gadolinium-functionalized CdHgTe/ZnS core/shell QDs are used for in vivo fluorescence and magnetic resonance imaging [27]. Cyclic arginine-glycine-aspartic acid conjugated micelle-encapsulated NIR CdTe/ZnSe QDs as highly luminescent probes for bio-labeling and in vivo imaging of pancreatic tumor in live mice [28]. In 2011, CdTe/CdSe QDs were also successfully applied for the fluorescence imaging of living animals (Figure 2(e)) [29].