ABSTRACT
Herein, a ratiometric fluorimetric nanosensor is introduced for the sensitive and selective analysis of chlorpromazine (CPZ) via employing blue-emitting B-doped carbon dots (B-CDs) as the reference fluorophore and green-emitting CdTe capped thioglycolic acid (TGA) quantum dots (TGA-CdTe-QDs) as the specific recognition probe. The sensor exhibits dual emission centered at 440 and 560 nm, under a single excitation wavelength of 340 nm. Upon the addition of ultra-trace amount of CPZ, the fluorescence signal of TGA-CdTe-QDs declines due to electron transfer process from excited TGA-CdTe-QDs to CPZ molecules, whereas the fluorescence peak of B-CDs is unaffected. Therefore, a new fluorimetric platform was prepared for the assay of CPZ in the range of 2.2 × 10-10 to 5.0 × 10-9 M with a detection limit of 1.3 × 10-10 M. Moreover, the practicability of the designed strategy was investigated for the detection of CPZ in biological samples and the results demonstrate that it possesses considerable potential to be utilized in practical applications.
Subject(s)
Cadmium Compounds , Carbon , Chlorpromazine , Quantum Dots , Spectrometry, Fluorescence , Quantum Dots/chemistry , Chlorpromazine/analysis , Carbon/chemistry , Cadmium Compounds/chemistry , Limit of Detection , Tellurium/chemistry , Humans , Fluorescence , Nanotechnology , Thioglycolates/chemistryABSTRACT
To explore in vivo application of quantum dots (QDs), it is essential to understand the dynamics and energetics of interactions between QDs and proteins. Here, surface plasmon resonance (SPR) and molecular docking were employed to investigate the kinetics and thermodynamics of interactions between human serum albumin (HSA) and CdTe QDs (~3 nm) functionalized with mercaptopropionic acid (MPA) or thioglycolic acid (TGA). Kinetic analysis showed that HSA-QD interactions involved transition-complex formation. Despite the structural similarities between MPA and TGA, the [HSA-CdTe@TGA] formation by association of free HSA and QDs demanded 70% more energy and higher entropic gain (Ea-TGA= 65.10 and T∆Sa-TGA= 28.62 kJ mol-1) than the formation of [HSA-CdTe@MPA] (Ea-MPA = 38.13 and T∆Sa-MPA = 0.53kJ mol-1). While the [HSA-CdTe@MPA]° dissociation required higher energy and lower entropy loss (Ed-MPA = 49.96 and T∆Sd-MPA = - 32.18kJ mol-1) than the [HSA-CdTe@TGA]° dissociation (Ed-TGA= 30.78 and T∆Sd-TGA= - 51.12 kJ mol-1). The stability of [HSA-QDs]° was independent of the temperature and functionalizing group. However, the enthalpic and entropic components were highly affected by the substitution of MPA (ΔH° = - 11.83 and TΔS° = 32.72 kJ mol-1) with TGA (ΔH° = 34.31 and TΔS° = 79.73 kJ mol-1). Furthermore, molecular docking results indicated that the metal site on the QDs contributes to the stabilization of [HSA-QDs]°. Therefore, differences in QD functionalization and surface coverage densities can alter the HSA-QD interaction, thus their application.
Subject(s)
Cadmium Compounds/pharmacology , Serum Albumin, Human/metabolism , Sulfhydryl Compounds/chemistry , Tellurium/pharmacology , Thioglycolates/chemistry , Cadmium Compounds/chemistry , Entropy , Humans , Kinetics , Molecular Docking Simulation , Quantum Dots , Serum Albumin, Human/chemistry , Surface Plasmon Resonance , Tellurium/chemistry , ThermodynamicsABSTRACT
Vagina atrophy is a common symptom in women after menopause owing to decreasing estrogen levels. The most conventional treatment for this condition is estrogen cream. The shortcoming is its weak adhesion to the vagina mucus, thus requiring frequent daily application. In this study, BDDE was selected to crosslink and graft chitosan with thioglycolic acid, to form thiolated chitosan (CT) and improve the mucoadhesive properties of chitosan. Genistein was selected as the bioactive molecule that could exhibit estrogen-like properties for long-term treatment of vaginal atrophy. The efficacies of the materials were characterized and evaluated both in vitro and in vivo. Results showed that the mucoadhesive property of CT was approximately two-fold stronger against the constant flow than unmodified chitosan. CT with genistein (CT-G) was administered intravaginally every three days in vivo. It showed that the developed CT-G recover 54 % of the epithelium thickness of an atrophic vagina and ease vaginal atrophy.
Subject(s)
Atrophic Vaginitis/drug therapy , Chitosan/chemistry , Genistein/therapeutic use , Hydrogels/chemistry , Thioglycolates/chemistry , Animals , Atrophic Vaginitis/pathology , Caco-2 Cells , Cell Adhesion/drug effects , Cell Survival/drug effects , Drug Carriers/chemistry , Female , Genistein/chemistry , Genistein/metabolism , Genistein/pharmacology , Humans , Hydrogels/chemical synthesis , Hydrogels/pharmacology , Mice , Rats , Rats, Sprague-Dawley , Vagina/pathologyABSTRACT
Paraquat is one of the most toxic materials widely applied in agriculture in most countries. In the present study, a simple, innovative and inexpensive nano biosensor which is based on a thioglycolic acid (TGA) - CdTe@CdS core-shell nanocrystals (NCs) to detect paraquat, is suggested. The NCs based biosensor shows a linear working range of 10-100 nM, and limited detection of 3.5 nM. The proposed sensor that has been well used for the detection and determination of paraquat in natural water samples is collected from corn field and a canal located near to the corn field yielding recoveries as high as 98%. According to our findings, the developed biosensor shows reproducibility and high sensitivity to determine paraquat in natural water samples in which the amount of paraquat has low levels. The suggested method is efficiently applied to paraquat determination in the samples of natural water that are collected from a tap water and a canal located near to the cornfield.
Subject(s)
Fluorescent Dyes/chemistry , Nanoparticles/chemistry , Paraquat/analysis , Water Pollutants, Chemical/analysis , Biosensing Techniques , Cadmium Compounds/chemistry , Hydrogen-Ion Concentration , Sulfates/chemistry , Tellurium/chemistry , Thioglycolates/chemistryABSTRACT
The parasitizing stage (trophozoite) of the protozoan parasite Perkinsus olseni progresses to the dormant stage (prezoosporangium) immediately after the death of the host through physiologically and morphologically drastic changes. This development is reproducible in Ray's fluid thioglycollate medium (RFTM). In this study, supplementation with tissue extract from a host, the Manila clam, significantly improved the efficiency of development, as determined by the numbers and sizes of developed prezoosporangia. Similar results were seen following supplementation with boiled host tissue extract, which indicates that a thermally stable component of the host is required for the parasite's development. Subsequently, we found that a commercially available lipid concentrate significantly increased prezoosporulation without host tissue, suggesting that the lipids in host tissue enhance prezoosporangia development. Moreover, we determined that yeast extract, sodium thioglycollate, and sodium chloride were the only components of RFTM required for prezoosporulation. Based on these findings, we prepared a simple, host-free medium for P. olseni prezoosporulation-Lipid concentrate Yeast extract Medium (LpcYM)-consisting of yeast extract, lipid concentrate, sodium thioglycollate, and sodium chloride. We confirmed that the prezoosporangia developed in LpcYM produce zoospores that are infectious to Manila clams and that trophozoites of other Perkinsus species (P. marinus, P. honshuensis, and P. chesapeaki) also develop to prezoosporangia in this host-free medium. As LpcYM has the simplest composition of prezoosporulation media available thus far, it enables us to conduct molecular and biochemical studies examining the drastic transformation process of this parasite.
Subject(s)
Alveolata/growth & development , Bivalvia/parasitology , Culture Media/analysis , Sodium Chloride/chemistry , Thioglycolates/chemistry , Trophozoites/growth & development , Yeast, Dried/chemistry , AnimalsABSTRACT
Development of efficient fluorescent probes for detecting the overexpressed Mcl-1 protein in living cells is imperative for the diagnosis and treatment of cancers. In this paper, a new UMI-77 based fluorescent probe (DNSH), was synthesized and characterized. DNSH bound to the hydrophobic pockets of Mcl-1 protein tightly and the binding affinity was 20-fold higher than that of previous developed Mcl-1 probe. DNSH exhibited specific fluorescence response to Mcl-1 protein rather than other proteins. In the presence of Mcl-1 protein, fluorescence emission of DNSH can be switched on. Furthermore, fluorescence colocalization experiment demonstrated that DNSH can be successfully used for imaging mitochondrial Mcl-1 protein in human prostate cancer cells without a washing process. These results showed that DNSH may find useful applications in biological research such as tracking Mcl-1 protein in living biological specimens.
Subject(s)
Fluorescent Dyes/chemistry , Myeloid Cell Leukemia Sequence 1 Protein/analysis , Optical Imaging , Prostatic Neoplasms/diagnostic imaging , Sulfonamides/chemistry , Thioglycolates/chemistry , Dose-Response Relationship, Drug , Fluorescent Dyes/chemical synthesis , Humans , Male , Models, Molecular , Molecular Structure , Structure-Activity Relationship , Sulfonamides/chemical synthesis , Thioglycolates/chemical synthesisABSTRACT
Thiosulfate leaching combined with ion-exchange resins is an innovative alternative for gold recovery. According to the properties of activated carbon, it could replace resins in the gold recovery process, improve efficiency, and reduce operating cost. In this research, the adsorption process of gold thiosulfate complex on thiol-modified activated carbon was studied. Thioglycolic acid (ATG) was impregnated in activated carbon, and its adsorption ability was tested with synthetic solutions of gold and sodium thiosulfate (Au 10 mg·L-1, Na2S2O3 0.1 mol·L-1, pH = 10.0). Carbon was characterized by infrared spectroscopy, SEM-EDS, PZC titration, hardness number measures, and proximal analysis. Synthetic solutions were also characterized by UV-vis spectroscopy and cyclic voltammetry. The percentage of volatile material increased from 10.0 to 13.9% due to the impregnation process of ATG. Infrared spectra show characteristic bands of C-H, S-H, and C-S bonds. In the adsorption tests, the ATG-impregnated carbon achieved 91% of gold recovery, while the same amount of ATG in the liquid phase stirred with unmodified activated carbon reached 90% of gold recovery. The 44.9% of gold recovered with activated carbon impregnated with ATG was eluted with sodium cyanide ([NaCN] = 0.2 mol·L-1; [NaOH] = 0.25 mol·L-1; [CH3CH2OH] = 30% V/V; pH = 12.0; t = 24 h). These results suggest the gold transferred from the thiosulfate complex to a new gold thiolate complex.
Subject(s)
Charcoal/chemistry , Gold Sodium Thiosulfate/chemistry , Gold/chemistry , Sulfhydryl Compounds/chemistry , Thiosulfates/chemistry , Adsorption , Gold/isolation & purification , Hydrogen-Ion Concentration , Solutions/chemistry , Spectroscopy, Fourier Transform Infrared , Thioglycolates/chemistryABSTRACT
A fluorescence off-on sensing platform was developed based on thioglycolic acid-stabilized cadmium sulfide quantum dots (CdS QDs) as fluorescence probe for the sensitive and selective detection of 2,6-pyridinedicarboxylic acid (DPA) in spores. The fluorescence emission intensity of the quantum dots at 650 nm when excited at 460 nm was first quenched by mixing with europium ions (Eu3+) and then recovered after the addition of DPA. The interaction of DPA with Eu3+ relieved the quenching effect of Eu3+ toward CdS QDs. As the DPA concentration increases, the color of the probe changes from colorless to red. The method exhibits a wide linear range from 1 to 120 µM for DPA determination, with a detection limit of 0.2 µM. The CdS QDs based nanoprobe was successfully applied for sensitive determination of DPA released from bacteria spores. In this case, the detection limit is 3.5 × 104 CFU·mL-1. Graphical abstract An off-on fluorescence sensor for detecting anthrax markers -2,6-pyridinedicarboxylic acid though restoring the fluorescence of cadmium sulfide quantum dots quenching by europium ions.
Subject(s)
Anthrax/diagnosis , Cadmium Compounds/chemistry , Fluorescent Dyes/chemistry , Picolinic Acids/analysis , Quantum Dots/chemistry , Sulfides/chemistry , Bacillus subtilis/chemistry , Biomarkers/analysis , Fluorescence , Fluorescent Dyes/chemical synthesis , Solubility , Spectrometry, Fluorescence , Spores, Bacterial/chemistry , Thioglycolates/chemistry , Water/chemistryABSTRACT
DNA methylation is involved in the oncogenesis of head and neck squamous cell carcinoma and could be used for early detection of cancer to increase the chances of cure, but unfortunately diagnosis is usually made at late stages of the disease. In this work we developed genosensors to detect DNA methylation of the MGMT gene in head and neck cancer cell lines. The probe for MGMT promoter methylation was immobilized on gold electrodes modified with 11-mercaptoundecanoic acid (11-MUA) self-assembled monolayers (SAM). Detection was performed with electrochemical impedance spectroscopy, with clear distinction between methylated and non-methylated DNA from head and neck cell lines. The genosensor is sensitive with a low detection limit of 0.24 × 10-12 mol L-1. In addition, the cell lines FaDu, JHU28 and SCC25 for the MGMT gene, could be distinguished from the HN13 cell line which has a high degree of MGMT methylation (97%), thus confirming the selectivity. Samples with different percentages of MGMT DNA methylation could be separated in multidimensional projections using the visualization technique interactive document mapping (IDMAP). The genosensor matrix and the immobilization procedures are generic, and can be extended to other DNA methylation biomarkers.
Subject(s)
DNA Modification Methylases/genetics , DNA Repair Enzymes/genetics , Electrochemical Techniques , Fatty Acids/chemistry , Head and Neck Neoplasms/genetics , Sulfhydryl Compounds/chemistry , Thioglycolates/chemistry , Tumor Suppressor Proteins/genetics , Cell Line, Tumor , DNA Modification Methylases/metabolism , DNA Repair Enzymes/metabolism , Electrodes , Gold/chemistry , Head and Neck Neoplasms/metabolism , Humans , Methylation , Promoter Regions, Genetic/genetics , Spectrophotometry, Infrared , Tumor Suppressor Proteins/metabolismABSTRACT
Colorimetric sensor array is a sensitive, rapid, and inexpensive detection technology which simulates human olfaction system based on various organic dyes. In this work, a sensor array based on acid-sensitive CdTe QDs coupled with chemometrics method was developed and proved to be a rapid, accurate and sensitive method for identification of 32 kinds of Chinese traditional cereal vinegars (CTCV). The specificity of identification of this method was mainly depends on the organic acids and melanoidins of CTCV. Among them, organic acids can quench the fluorescence of QDs through enhancing their electron transfer (hydrogen bond) and resonance energy transfer, and the fluorescence intensity of melanoidin was closely related to the brewing technology and aging year of CTCV. The types and aging time of 32 CTCV can be 100% identified at a dilution of 1000 by partial least squares discriminant analysis, when the latent variables were 4. And only one kind of QDs is needed instead of various organic dyes to this kind of colorimetric sensor array. Except for vinegar, this method can also be used in the identification of other food which rich in organic acid.
Subject(s)
Acetic Acid/analysis , Colorimetry/instrumentation , Quantum Dots/chemistry , Cadmium Compounds/chemistry , Fluorescence , Hydrogen-Ion Concentration , Solutions , Tellurium/chemistry , Thioglycolates/chemistryABSTRACT
I-III-VI chalcopyrite ternary quantum dots have emerged as a good alternative over the conventional II-VI and IV-VI chalcogenide binary QDs that usually consist of heavy metals such as Cd and Pb which has limited their bioapplications. Among the chalcopyrite QDs, AgInSe2 QDs has been the least developed due to the imbalanced cation reactivity, unwanted impurities, broad size distribution and resultant large particle sizes. In addition, the cell viability of these QDs still needs to be investigated on different cell lines both normal and cancerous ones. Herein, large-scale synthesis of water-soluble thioglycolic acid (TGA) capped and gelatin-stabilized AgInSe2 (AISe) core and AgInSe2/ZnSe (AISe/ZnSe) core/shell QDs in the absence of an inert atmosphere and their cell viability against different cell lines are reported. The optical and structural characteristics of the as-synthesized QDs were investigated by UV-visible (vis) absorption, photoluminescence (PL) and Fourier-transmission infrared (FTIR) spectroscopies, dynamic light scattering (DLS), X-ray diffraction (XRD), and high-resolution transmission electron microscope (HRTEM) techniques. Growth of ZnSe shell on the core AISe resulted in the blue shifting of the emission maximum position with the increased PL intensity. The QDs are small and spherical in shape with an average particle diameter of 2.8â¯nm and 3.2â¯nm for AISe and AISe/ZnSe QDs respectively. The in vitro cell viability assay revealed that the as-synthesized AISe/ZnSe QDs are not toxic towards cancerous (HeLa -cervical cancer and A549-lung cancer) and normal (BHK21 -Kidney) cell lines.
Subject(s)
Quantum Dots/chemistry , Thioglycolates/chemistry , Water/chemistry , Cell Survival/physiology , Dynamic Light Scattering , Humans , Selenium Compounds/chemistry , Spectroscopy, Fourier Transform Infrared , X-Ray Diffraction , Zinc Compounds/chemistryABSTRACT
Because of its versatile coordination modes and strong coordination ability, the mercaptoacetic acid substituted 1,2,4-triazole 2-{[5-(pyridin-2-yl)-4H-1,2,4-triazol-3-yl]sulfanyl}acetic acid (H2L) was synthesized and characterized. Treatment of H2L with cobalt and nickel acetate afforded the dinuclear complexes {µ-3-[(carboxylatomethyl)sulfanyl]-5-(pyridin-2-yl)-4H-1,2,4-triazol-4-ido-κ2N1,N5:N2,O}bis[aqua(methanol-κO)cobalt(II)] methanol disolvate, [Co2(C9H6N4O2S)2(CH3OH)2(H2O)2]·2CH3OH (1), and {µ-3-[(carboxylatomethyl)sulfanyl]-5-(pyridin-2-yl)-4H-1,2,4-triazol-4-ido-κ2N1,N5:N2,O}bis[diaquanickel(II)] methanol disolvate dihydrate, [Ni2(C9H6N4O2S)2(H2O)4]·2CH3OH·2H2O (2), respectively. Complex 1 crystallized in the monoclinic space group P21/c, while 2 crystallized in the tetragonal space group I41/a. Single-crystal X-ray diffraction studies revealed that H2L is doubly deprotonated and acts as a tetradentate bridging ligand in complexes 1 and 2. For both of the obtained complexes, extensive hydrogen-bond interactions contribute to the formation of their three-dimensional supermolecular structures. Hirshfeld surface analysis was used to illustrate the intermolecular interactions. Additionally, the urease inhibitory activities of 1, 2 and H2L were investigated against jack bean urease, where the two complexes revealed strong urease inhibition activities.
Subject(s)
Acetates/chemistry , Cobalt/pharmacology , Coordination Complexes/chemistry , Nickel/pharmacology , Organometallic Compounds/chemistry , Thioglycolates/pharmacology , Urease/antagonists & inhibitors , Urease/chemistry , Cobalt/chemistry , Crystallography, X-Ray , Hydrogen Bonding , Ligands , Models, Molecular , Nickel/chemistry , Thioglycolates/chemistryABSTRACT
The authors have synthesized a phosphorescent probe of type SiO2-QD-MIP, where QD stands for Mn:ZnS quantum dots and MIP is a polymer coating that was molecularly imprinted with cephalexin. The nanoprobe with high specificity was prepared via sol-gel polymerization using thioglycolic acid (TGA)-modified QDs as luminescent materials, cephalexin as the template, 3-aminopropyltriethoxysilane as the functional monomer, and tetraethoxysilane as the crosslinking agent. The SiO2-QD-MIPs were characterized by X-ray powder diffraction, transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectrometry. The orange emission of the probe, with excitation/emission maxima at 295/590 nm, decreases linearly in the 2.5-50 µg·L-1 cephalexin concentration range with a limit of detection (LOD) of 0.81 µg·L-1. The nanoprobe was successfully applied to the determination of cephalexin in (spiked) raw milk and milk powder. The recoveries ranged from 91.7 to 103.7%.
Subject(s)
Cephalexin/analysis , Luminescent Agents/chemistry , Molecular Imprinting , Polymers/chemistry , Quantum Dots/chemistry , Thioglycolates/chemistry , Luminescent Agents/chemical synthesis , Manganese/chemistry , Molecular Structure , Particle Size , Porosity , Sulfides/chemistry , Surface Properties , Zinc Compounds/chemistryABSTRACT
Lefamulin (BC-3781) is the first systemic pleuromutilin antibiotic found to be safe and effective in the treatment of community-acquired bacterial pneumonia (CABP) in humans. This novel antibiotic was developed to combat the increasing incidence of bacterial resistance to current therapies. As the first semisynthetic pleuromutilin for systemic use in humans, lefamulin has demonstrated efficacy against the most common bacteria responsible for CABP, including strains exhibiting resistance to macrolides, fluoroquinolones, tetracyclines, vancomycin, and beta-lactams. In vitro studies have demonstrated efficacy against Staphylococcus aureus, beta-hemolytic and viridans group streptococci, coagulase-negative staphylococci, Enterococcus faecium, Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophilia, and Moraxella catarrhalis at MIC values lower than those of currently available therapies. Two phase III trials (LEAP-1 and LEAP-2) have demonstrated similar findings, meeting non-inferiority criteria for CABP with a minimal side-effect profile. Pharmacokinetic and pharmacodynamic evaluations have shown sufficient drug levels in plasma, subcutaneous adipose tissue, skeletal muscle, and epithelial lining fluid, warranting further investigation for other clinical uses. Lefamulin was approved by the United States Food and Drug Administration (FDA) on 19 August 2019 for the treatment of CABP.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Community-Acquired Infections/drug therapy , Community-Acquired Infections/microbiology , Diterpenes/pharmacology , Pneumonia, Bacterial/drug therapy , Polycyclic Compounds/pharmacology , Thioglycolates/pharmacology , Anti-Bacterial Agents/chemistry , Diterpenes/chemistry , Humans , Microbial Sensitivity Tests , Molecular Conformation , Pneumonia, Bacterial/microbiology , Polycyclic Compounds/chemistry , Thioglycolates/chemistryABSTRACT
Despite the increasing availability of antibiotics with activity against pathogens that cause community-acquired pneumonia (CAP), CAP remains a major cause of morbidity, hospital admissions and re-admissions, and mortality. Lefamulin is a novel pleuromutilin antibiotic with potent in vitro activity against both typical and atypical CAP pathogens. In this review of the medical literature, we summarize the available information, including mounting clinical evidence, about lefamulin and its potential value in CAP.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacteria/drug effects , Diterpenes/pharmacology , Diterpenes/therapeutic use , Pneumonia/drug therapy , Polycyclic Compounds/pharmacology , Polycyclic Compounds/therapeutic use , Thioglycolates/pharmacology , Thioglycolates/therapeutic use , Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Bacteria/isolation & purification , Community-Acquired Infections/drug therapy , Community-Acquired Infections/microbiology , Diterpenes/adverse effects , Diterpenes/chemistry , Humans , Molecular Structure , Pneumonia/microbiology , Polycyclic Compounds/adverse effects , Polycyclic Compounds/chemistry , Ribosome Subunits, Large, Bacterial/drug effects , Thioglycolates/adverse effects , Thioglycolates/chemistry , Treatment Outcome , PleuromutilinsABSTRACT
In this work, we reported a novel "one-pot" strategy for preparation of chitosan-coated carbon nanotubes (CNTs) composites via a combination of Diels-Alder (DA) reaction and mercaptoacetic acid locking imine (MALI) reaction for the first time. To evaluate the adsorption characteristics, the as-prepared samples were applied to remove copper ions (Cu2+) from aqueous solution. The effects of contact time, solution pH, temperature and initial Cu2+ concentration on the adsorption of Cu2+ onto the as-prepared samples were investigated. The chitosan modified CNTs composites showed high affinity and fast kinetics for the adsorption of Cu2+ ions, and adsorption capacity of the composites was found to be 2 times that of pristine CNTs. Adsorption kinetics and thermodynamic indicated a spontaneous and endothermic nature of the adsorption of Cu2+ on the surface of chitosan-coated CNTs composites, kinetically obeyed the pseudo-second-order model. Equilibrium data could be best described by the Langmuir isotherm model, with a maximum monolayer adsorption capacity of 115.84â¯mg/g. In view of the extensive applicability of DA chemistry and MALI reaction, different carbon nanomaterials based composites with various functional groups could be fabricated and applicable to different fields such as environmental catalysis and biomedicine.
Subject(s)
Chitosan/chemistry , Copper/chemistry , Copper/isolation & purification , Nanotubes, Carbon/chemistry , Thioglycolates/chemistry , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/isolation & purification , Adsorption , Hydrogen-Ion Concentration , Kinetics , Models, Molecular , Molecular Conformation , TemperatureABSTRACT
The chemiluminescence (CL) behaviour of the luminol-potassium periodate system enhanced by CdTe quantum dots capped with thioglycolic acid (TGA-CdTe QDs) was studied using kinetic experiments, CL spectra, UV-vis absorption spectra and fluorescence spectra. The production of oxygen-containing reactant intermediates (O2 â¢- and OH⢠) in the present CL system was verified by CL. The possible CL mechanism was discussed in detail. Furthermore, theophylline (THP) was determined based on its enhancement of the CL intensity of the CdTe QDs-luminol-potassium periodate system coupled with a flow-injection technique. Under these optimized conditions, the linear range was found to be from 1.0 × 10-8 to 1.0 × 10-5 g/mL with a detection limit of 2.8 × 10-9 g/mL (3σ). The recoveries for the determination of THP in tablets were from 98.2 to 99.6%.
Subject(s)
Flow Injection Analysis , Luminescent Measurements , Quantum Dots/chemistry , Theophylline/analysis , Cadmium Compounds/chemistry , Luminescence , Luminol/chemistry , Periodic Acid/chemistry , Potassium Compounds/chemistry , Spectrometry, Fluorescence , Tellurium/chemistry , Thioglycolates/chemistryABSTRACT
Keratin has been attracting interest due to its stability against enzymatic degradation thereby allowing more predictable degradation profile for tissue regeneration applications. While the efficacy of keratin has been demonstrated in different tissue models, there has been no systematic study to investigate and compare the different routes of keratin extraction from human hair. Here, we compared the four commonly used extraction methods and highlighted both physical and chemical differences in the extracted keratin. Keratin was extracted from human hair using one of four common agents, namely, sodium sulfide, peracetic acid, urea and thioglycolic acid. Whereas no specific trend was observed, the keratin extracted through peracetic acid method had significantly different properties. It resulted in lowest yield of 52⯵g/mL and low crystallinity but the protein formed aggregates with highest hydrodynamic average size of around 283â¯nm compared to the other three methods. However, despite greater aggregation, keratin extracted from peracetic acid method exhibited secondary structural conformation similar to thioglycolic acid method. All the four extracted keratin promoted cellular proliferation of osteoblasts compared to the uncoated surface. These results provide new insight into the extraction of keratin from human hair with implications for its use as a biomaterial.
Subject(s)
Chemical Fractionation/methods , Hair/chemistry , Keratins/isolation & purification , Humans , Keratins/chemistry , Particle Size , Peracetic Acid/chemistry , Protein Structure, Secondary , Thioglycolates/chemistryABSTRACT
A simple, cheap, sensitive and selective probe for determination of DNPH in wastewater using thioglycolic acid (TGA)-coated CdTe QDs (TGA-QDs) as fluorescence probe has been established, and the properties of CdTe QDs were characterized by TEM, FT-IR, DLS, XRD and zeta potentials. CdTe QDs fluorescence is highly efficiently quenched after adding DNPH on account of electron transfer effect, and the fluorescence quenching behavior of CdTe QDs interaction with DNPH is static quenching process. A good linear relationship is observed between the relative fluorescence intensity (F0 /F) and 0.06-10 ng mL-1 of DNPH. As compared with some of reported methods, LOD of this method for analysis of DNPH (0.23 ng mL-1 ) is the lowest. Masking agents of DDTC and NH4 OH can eliminate the interference of Cu2+ , Ag+ and Hg2+ . Hence, DNPH can be selectively and accurately detected and the established method was successfully used for detecting DNPH in wastewater with acceptable recovery of 90.6-102%.
Subject(s)
Cadmium Compounds/chemistry , Fluorescent Dyes/chemistry , Phenylhydrazines/analysis , Quantum Dots/chemistry , Tellurium/chemistry , Wastewater/chemistry , Water Pollutants, Chemical/analysis , Limit of Detection , Microscopy, Electron, Transmission , Scattering, Radiation , Spectroscopy, Fourier Transform Infrared , Thioglycolates/chemistry , X-Ray DiffractionABSTRACT
Current research work was conducted to synthesize Thiol modified arabinoxylan and its application in fabrication of hydrogel. Thioglycolic acid was esterified with arabinoxylan to prepare Thiolatedarabinoxylan. Appearance of peak at 2533.34 cm-1 in FTIR and thiol content showed successful thiolation. The pH-dependent Thiolatedarabinoxylan/acrylic acid (TAX/AA) hydrogels of perindopril erbumine were prepared via free-radical co-polymerization. Perindopril erbumine (PE) was employed as model drug. Different batches with different feed ratio of TAX, AA, and MBA were prepared and their influence on swelling, solvent penetration, and consequent drug release was investigated. Swelling coefficients increased with increase in pH. TAX/AA hydrogels were characterized by Fourier-transform infrared spectroscopy (FT-IR), Thermal Analysis (TA), X-Ray diffraction (XRD), and scanning electron microscope (SEM). Dissolution studies were performed at pH 1.2 and 7.4 in which drug release showed direct correlation with TAX and AA ratio. In vivo studies showed that Cmax of TAX-co-AA based hydrogel was 81.57 ± 0.35 ng/ml which was maintained for a longer time after its administration. All the results of in vivo studies were significant and TAX-co-AA based hydrogel enhances the bioavailability of perindopril erbumine.