Thioglycolic Acid Research Articles

Effects of Thioglycolate Compounds in an Emerging Technique in the World of Cosmetics-Brow Lamination.

The side effects of two related chemicals, ammonium thioglycolate (ATG) and thioglycolic acid (TGA) have been widely highlighted in the world of cosmetics. These thioglycolate compounds are considered essential ingredients in a new technique known as brow lamination. This technique is widely used nowadays, with the aim of changing the eyebrow shape. To our knowledge, this is the first study to address the possible side effects of brow lamination. The hydrophilic characteristic of ATG and TGA reflects their transdermal absorption through the intracellular and transappendageal pathways. These compounds can affect the skin through allergic contact dermatitis (ACD), characterized by skin irritation, dryness, and erythema. Moreover, these thioglycolates can alter several mechanical and chemical reactions in the eyebrows' hair, therefore affecting their shape, structure, and pigmentation. In addition, these chemicals contained in brow lamination can exert systemic manifestations, at the level of the reproductive, ocular, respiratory, and endocrine systems. More studies should be elaborated to shed light on the possible side effects of this trend. Additionally, further regulations should be taken into consideration to ensure the concentration and the measures applied are convenient to minimize these side effects.

A Novel PCR-Free Ultrasensitive GQD-Based Label-Free Electrochemical DNA Sensor for Sensitive and Rapid Detection of Francisella tularensis

Biological warfare agents are infectious microorganisms or toxins capable of harming or killing humans. Francisella tularensis is a potential bioterrorism agent that is highly infectious, even at very low doses. Biosensors for biological warfare agents are simple yet reliable point-of-care analytical tools. Developing highly sensitive, reliable, and cost-effective label-free DNA biosensors poses significant challenges, particularly when utilizing traditional techniques such as fluorescence, electrochemical methods, and others. These challenges arise primarily due to the need for labeling, enzymes, or complex modifications, which can complicate the design and implementation of biosensors. In this study, we fabricated Graphene Quantum dot (GQD)-functionalized biosensors for highly sensitive label-free DNA detection. GQDs were immobilized on the surface of screen-printed gold electrodes via mercaptoacetic acid with a thiol group. The single-stranded DNA (ssDNA) probe was also immobilized on GQDs through strong π−π interactions. The ssDNA probe can hybridize with the ssDNA target and form double-stranded DNA, leading to a decrease in the effect of GQD but a positive shift associated with the increase in DNA concentration. The specificity of the developed system was observed with different microorganism target DNAs and up to three-base mismatches in the target DNA, effectively distinguishing the target DNA. The response time for the target DNA molecule is approximately 1010 s (17 min). Experimental steps were monitored using UV/Vis spectroscopy, Atomic Force Microscopy (AFM), and electrochemical techniques to confirm the successful fabrication of the biosensor. The detection limit can reach 0.1 nM, which is two–five orders of magnitude lower than previously reported methods. The biosensor also exhibits a good linear range from 105 to 0.01 nM and has good specificity. The biosensor’s detection limit (LOD) was evaluated as 0.1 nM from the standard calibration curve, with a correlation coefficient of R2 = 0.9712, showing a good linear range and specificity. Here, we demonstrate a cost-effective, GQD-based SPGE/F. tularensis DNA test suitable for portable electrochemical devices. This application provides good perspectives for point-of-care portable electrochemical devices that integrate sample processing and detection into a single cartridge without requiring a PCR before detection. Based on these results, it can be concluded that this is the first enzyme-free electrochemical DNA biosensor developed for the rapid and sensitive detection of F. tularensis, leveraging the nanoenzyme and catalytic properties of GQDs.

Outstanding performance of Co-doped ZnS nanoparticles used as nanocatalyst for synthetic dye degradation

In this work, fabrication of pure and cobalt (Co) doped zinc sulfide (ZnS) nanoparticles were carried out via facile co-precipitation technique using thioglycolic acid as a surfactant. The synthesized nano powders were employed to characterize using various techniques like X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and UV–Vis spectroscopy, to elucidate the alterations in the structure and morphology of nanomaterials. The XRD analysis revealed wurtzite phase of fabricated nanoparticles. Inclusion of Co dopants failed to modify the lattice structure of host material. Analysis of UV–Vis spectroscopy indicates intensive absorption in the visible region upon doping. FTIR spectroscopy was employed to identify functional groups affiliated with molecular vibrations. The photoactivity and kinetics of photo-products were evaluated by monitoring degradation of methylene blue (MB) by solar irradiation. Photodecomposition of MB was significantly increased when Co doped ZnS was employed relative to pristine ZnS. This novel technique of doped ZnS nanoparticles provide an effectual and sustainable route for treatment of wastewater.

Triethanolamine-modified poloxamer temperature-sensitive hair care gel for intelligent controlled release of sodium thioglycolat

Abstract A triethanolamine-modified poloxamer temperature-sensitive hair care gel was formulated in order to reduce the adverse health effects associated with sodium thioglycolate (TGA(Na)), the active component in hair treatment agents, while maintaining excellent efficacy. It was found that TEA-3 gelled at 32 °C with a triethanolamine concentration of 3 %. This formulation exhibited a reversible phase transition, transitioning to a solid state upon contact with the scalp (>32 °C) and reverting to a liquid state when in contact with hair (<32 °C). The release behavior of TGA(Na) from the gel was assessed by both in vitro release studies and transdermal experiments. In addition, it was observed that the triethanolamine-modified poloxamer gel exhibited improved hair care efficiency compared to conventional hair care agents. These results suggest that the triethanolamine-modified poloxamer gel is a promising alternative to conventional hair care products, offering improved efficacy while minimizing potential adverse health effects.

A Study on a Method of Detecting Heavy Metal Content Using Thioglycolic Acid and Quartz Crucible

In the Chinese Pharmacopoeia, the method of detecting heavy metals commonly uses thioglycolic acid. It is often used as a special method for the limit check of heavy metals in raw pharmaceutical or cosmetic raw materials. Traditional use of porcelain crucibles in sample pretreatment may result in false positive reactions. This study used quartz crucibles to replace the traditional porcelain crucibles to study the possibility of contamination. It was found that the false negative reactions caused by crucible material can be eliminated, and the precision of the method was verified by detecting three batches of samples. The method has good repeatability and accuracy. It can replace the use of traditional porcelain crucibles in the method of detecting heavy metals with thioglycolic acid.

Synthesis of New Heterocyclic Derivatives from 4-(3, 5-Dimethyl-1-phenyl-1H-pyrazol-4-ylazo)- benzoic acid

In this work pyrazolin derivatives were prepared from the diazonium chloride salt of 4-aminobenzoic acid. Azo compounds were prepared from the reaction of an ethanolic solution of sodium acetate and calculated amount of active methylene compound namely, acetyl acetone to obtain the corresponding hydrazono derivative (1). Cyclocondensation reaction of compounds (1) with hydrazine hydrate and phenyl hydrazine in boiling ethanol affording the corresponding pyrazoline-5-one derivatives of 4-aminobenzoic acid (2,3). Then compound (3) was reacted with thionyl chloride to give the corresponding acid chloride derivative(4), followed by conversion into the corresponding acid hydrazide derivative (5) carboxylic acid thiosemicarbazide (11), esters (14,15), thioesters (16,17) and amides (18,19), when treated hydrazine hydrate, thiosemicarbazide, alcohols, alkylthiol and secondary amines in dry refluxing benzene; respectively. Schiff's bases (6-8) were prepared by refluxing of compound (5) with different aldehydes and ketons, then two compounds from the Schiff's bases were cyclized with ?-mercapto acetic acid to give (9 and 10). Furthermore, 1,2,4-triazole derivative (12) have been also prepared by refluxing thiosemicarbazide derivative with sodium hydroxide solution (4%) followed acidification of the result using (10%)hydrolic acid. Moreover, a thiadiazole derivative (13) has been prepared by treatment of thiosemicarbazide derivative with concentrated sulfuric acid as cyclyzing agent. Finally, oxadiazole derivative (20) has prepared by condensation of its acid hydrazide derivative with carbon disulfide in basic medium.

Synthesis of Thioglycolic Acid-Modified Molybdenum Disulfide Nanosheets for Electrochemical Sensing and Its Application in Molnupiravir Detection

In the modern world, population growth, industrialization, and lifestyle changes have led to a rise in existing and new diseases, increasing global drug consumption. Proper pharmaceutical dosage is vital since drugs are only effective within specific concentration ranges. Therefore, developing reliable analytical methods for drug analysis in pharmaceuticals and biological samples is essential. Electroanalytical methods are particularly advantageous due to their low cost, ease of use, and rapid response. This study introduces a highly sensitive electrochemical sensor based on thioglycolic acid (TA)-decorated metallic phase molybdenum disulfide (MP-MoS2) nanosheets for the selective detection of molnupiravir (MOL), an antiviral drug used in Covid-19 treatment. The TA@MP-MoS2 nanomaterial was characterized using FTIR, TEM, and EIS. Screen-printed carbon electrodes (SPCE) were modified with TA@MP-MoS2 nanosheets to evaluate their electro-chemical and catalytic behaviours towards MOL by cyclic voltammetry (CV) and square wave voltammetry (SWV). The sensor displayed a well-defined electro-oxidation signal for MOL at 0.534 V, with the linear responses in two concentration ranges: 0.50–3.40 μM and 3.40–9.55 μM, and a low detection limit of 22.6 nM. The proposed design that has promising results could be an alternative strategy to fabricate the sensitive sensor for the detection of antiviral agents in real samples.

Synthesis, Characterization and Antifungal Studies of Novel Substituted Benzaldehyde Derivatives of 2-Amino-6-ferrocenyl-4-phenylpyrimidine

A series of novel 2-amino-6-ferrocenyl-4-phenylpyrimidine (AFPP) derivatives (6a-j) have been synthesized by coupling AFPP with thioglycolic acid and various substituted benzaldehydes (a-j) using standard 1,3-dicyclohexylcarbodiimide (DCC) protocol. The synthesized compounds were characterized by FTIR, 13C NMR, 1H NMR and MS techniques. The synthesized compounds 6a-j were evaluated for antifungal activities against Candida albicans MTCC 183. Comparing compounds 6a-j to standard amphotericin B, it was found that the synthesized compounds showed excellent activity.

Mechano‐Electrochemical Behavior of Nanostructured Li‐ and Mn‐Rich Layered Oxides with Superior Capacity Retention and Voltage Decay for Sulfide‐Based All‐Solid‐State Batteries

AbstractLi‐ and Mn‐rich layered oxides (LMROs) are recognized as promising cathode materials for lithium‐ion batteries (LIBs) due to their high specific capacity and cost efficiency. However, LMROs encounter challenges such as manganese dissolution in electrolytes and the release of oxygen gas from irreversible oxygen redox reactions, leading to structural degradation and voltage decay that reduce energy density. Consequently, recent research has shifted toward employing LMROs in all‐solid‐state batteries (ASSBs), where Mn dissolution is negligible. Herein, nanostructured LMROs demonstrate superior electrochemical compatibility with sulfide‐based solid electrolytes in ASSBs compared to conventional LIBs. Nanostructured LMRO exhibits outstanding capacity retention (97.1% after 1300 cycles at 30 °C) with significantly suppressed voltage decay. Furthermore, the initial electrochemical activation of Li2MnO3 domains within LMRO is explored in terms of the mechano‐electrochemical interactions in the composite cathode. At elevated temperatures, interfacial degradation accelerates due to the chemical oxidation of Li6PS5Cl solid electrolytes, driven by oxygen released from LMRO. To address this, LMRO surfaces are modified with thioglycolic acid through esterification, suppressing interfacial degradation of Li6PS5Cl and ensuring stable capacity retention over 500 cycles at 60 °C. These findings underscore the potential of LMRO materials as promising cathode options for ASSBs, surpassing those used in LIBs.

Microwave-assisted green synthesis and molecular docking study of some new 4-thiazolidinone derivatives as possible bioactive agents

We have developed an economical and environmentally friendly microwave-assisted efficient method for the synthesis of a series of new 4-oxo-thiazolidine derivatives (4a-d). The method involves microwave irradiated cyclocondensation reaction of Schiff bases (3a-d) and thioglycolic acid in drug master file (DMF). 4-oxo-thiazolidine derivatives (4a-d) was also synthe 4-Oxo-Thiazolidine derivatives were also synthesized by conventional heating procedures and consequence were Compared with Microwave assisted green method. The results suggest that microwave-assisted syntheses lead to higher yields within very short reaction times. Antimicrobial screening of all the synthesized compounds was carried out using Gram-positive strains Staphylococcus aureus and Gram-negative strain encompassing Escherichia coli, Proteus vulgaris, and Salmonella typhi. The results were compared with the standard drug chloramphenicol. All the synthesized compounds were subsequently examined using molecular docking experiments against peptide deformylase (PDB ID: 1G2A), which evaluates the binding interaction of ligands with enzyme active sites.. KEYWORDS :Microwave irradiation, Thiazolidinone, Molecular docking, Peptide deformylase, Antimicrobial screening.

Sonochemical synthesis of bismuth sulfide-based nanorods for hydrogen production

Bismuth-based nanostructures have been used as promising materials for catalytic hydrogen production. Herein, a sonochemical method was developed to prepare solid solutions like Bi2-xZn1.5xS3 in order to strengthen the Bi2S3 redox ability. Thioglycolic acid (TGA) was used as a complexing agent of Bi3+ to slow down Bi2S3 precipitation, making zinc insertion into the sulfide structure easier. The results of XRD, TEM, EDS, XPS, and DRS analyses suggest the formation of nanocomposites consisting of nanorods of Bi2-xZn1.5xS3 covered by ZnS nanoparticles, with bandgap widening from 1.16 eV (Bi2S3) to 2.37 eV (Bi1.53Zn0.6S3/ZnS/Zn(OH)2). The hydrogen generation in an ethanol aqueous solution was investigated under sonolysis, photocatalysis and simultaneous sonolysis and photocatalysis (sonophotocatalysis) in the presence of bismuth sulfide-based nanorods. The hybrid action of light and ultrasounds determined a remarkable synergistic effect on the hydrogen production of the solid solutions. The most outstanding results were found in the presence of nanocomposites containing Bi2-xZn1.5xS3, which can have an origin in better charge separation after zinc incorporation.

Effective removal of textile dye via synergy of adsorption and photocatalysis over ZnS nanoparticles: Synthesis, modeling, and mechanism

In this work, we prepared sulfur-zinc nanoparticles (ZnS-TGA) functionalized with thioglycolic acid by a hydrothermal method and tested their photodegradation ability by solar irradiation. ZnS-TGA were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), high-resolution transmission electron microscope (HR-TEM), UV–Vis spectrophotometer and photoluminescence spectroscopy. In the characterization of these nanoparticles, thioglycolic acid proved to be a strong capping ligand, with a specific surface area of 36.82 m2/g and an average size of 7.15 nm. To test the photocatalytic degradability of the product, methylene blue (MB) was used as a model pollutant. Various operational variables were investigated, including pH, amount of nanoparticles, dye concentration, contact time and temperature. The equilibrium adsorption tests, and the statistical physical calculations allowed the analysis of the energetic and steric variables of the adsorption of MB dye molecules on the surface of these nanoparticles. The equilibrium data were well fitted with Langmuir-Freundlich (L-F) and the adsorption kinetics with pseudo-first order. The maximum adsorption capacity of the MB dye removal process was 30.92 mg g−1 at pH 7 and 298 K, and this process was spontaneous and exothermic. The dye molecules and the surface of the nanoparticles exhibited physical interactions with adsorption energies of 23.31–25.92 kJ/mol. The photocatalytic activity of these nanoparticles resulted in a dye degradation efficiency of 91.1 % in 180 min. The photocatalytic efficiency remained almost unchanged after five consecutive degradation cycles, resulting in a methylene blue degradation of 85 %. According to these results, these environmentally friendly nanoparticles have the potential to purify industrial and urban liquids contaminated with harmful organic compounds such as dye molecules.

Ultrasound assisted solvent-free approach for the synthesis of 4-thiazolidinone derivatives

An economical and environment-friendly protocol involving the use of ultrasonic vibrations was developed for the synthesis of a series of diaryl-4-thiazolidinones. The highlights of the developed approach are significant enhancement in the product yield, short reaction time, solvent-free, free of any toxic metal as a catalyst, cheaper synthetic methodological approach as well as non-formation of side-products. The developed approach is useful in terms of immense biological relevance of thiazolidines as well as the greener approach for cyclo-condensation of functionalized imines with thioglycolic acid.

Fabrication of Glucose Fluorescent Aptasensor Based on CdTe Quantum Dots.

Diabetes is a chronic metabolic disease characterized by high blood glucose (or blood sugar) levels, which harms the heart, blood vessels, eyes, kidneys, and nerves over time. So, it is crucial to regularly control glucose concentration in biological fluids to check its targets, reduce unpleasant symptoms of high and low blood sugar, and avoid long-term diabetes complications. This study developed a simple, rapid, sensitive, and cost-effective fluorescence system for glucose determination. The fluorescent Aptasensor was fabricated using cadmium telluride quantum dots (CdTe QDs) modified with thioglycolic acid and functionalized with thiol-glucose-aptamer through ligand exchange. The thiol-glucose-aptamer interacted directly with CdTe QDs, increasing fluorescence intensity. However, it decreased when the target molecules of glucose were introduced. The structural and morphological characteristics of the Aptasensor were confirmed by various analytical methods such as UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy dispersive x-ray spectroscopy (EDX), transmission electron microscopy (TEM), atomic force microscopy (AFM), and dynamic light scattering (DLS). According to the typical Stern-Volmer equation, the relationship between fluorescent quenching and target concentration was linear with a detection limit (LOD) of 0.13 ± 1.95 × 10-11 mol L-1 and a relative standard deviation (RSD) of 1.05%. The Aptasensor demonstrated high specificity towards the target and stability over 28 days. Furthermore, it detected glucose in human serum and urine with a recovery rate of up to 99.74%. The results indicate that the fluorescent Aptasensor could be valuable in developing robust sensing technology for low-concentrated analytes.

Efficient Mercury Ion Detection in Water: CdTe/CdS/ZnS Quantum Dots as a Simple, Sensitive, and Rapid Fluorescence Sensor.

Mercury (Hg), a notorious heavy metal with detrimental impacts on human health and the environment, necessitates the development of precise measurement methods. This study introduces an expeditious and straightforward photochemical approach to synthesize thioglycolic acid (TGA)-stabilized CdTe/CdS/ZnS core/multi-shell quantum dots (QDs). The synthesized CdTe/CdS/ZnS QDs were comprehensively characterized using fluorescence spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), Field Emission Scanning Electron Microscopy (FESEM), and X-Ray diffraction (XRD). XRD and EDS results confirmed the successful formation of CdTe/CdS/ZnS structure. Also, FESEM and TEM results showed that CdTe/CdS/ZnS QDs were spherical. Results showed that synthesized Exhibiting vibrant green fluorescence and notable quenching in the presence of Hg2+ ions, these QDs emerge as promising candidates for fabricating a fluorescent sensor. The proposed sensor demonstrates notable sensitivity to Hg2+, featuring a detection limit of 16.32 nM and a linear range from 20 nM to 70 nM. The sensor's selectivity was confirmed by analyzing various anions and cations. Moreover, when tested with tap water, river water, and agricultural samples, the sensor exhibited reliable performance, validated by Inductively Coupled Plasma (ICP) analysis. Additionally, CdTe/CdS/ZnS QDs immobilized on micro pads proved effective for on-site water sample analysis, presenting a versatile solution for environmental monitoring.

Shopping around: Comparing Cd(II) sorption performance of disparate functional groups-modified microcrystalline cellulose composites

The structure-function relationship of functionalized microcrystalline cellulose (MCC) composites as adsorbents remains unclear. Herein, the orange peel-derived MCC (i.e., OP-OH-H-25) was treated by different functional agents to prepare adsorbents for cadmium (Cd(II)) removal. Mercaptoacetic acid and orthophosphoric acid did not apparently impact MCC's surface site types and contents. Alternatively, they efficiently purified OP-OH-H-25 and generated OP-OH-SH and OP-OH-P samples with increased cellulose amounts. In contrast, the glycine modification produced OP-OH-NH2 with fewer sulfhydryl/carboxyl functional groups and more amide/amino sites. The pH-dependent Cd(II) removal trends by the MCC-related materials showed three successive stages with disparate sorption modes. The Cd(II) sorption kinetics processes on OP-OH-SH, OP-OH-P, and OP-OH-NH2 reached equilibrium after 0.25 h, faster than 0.5 h on OP-OH-H-25. The maximum Cd(II) sorption capacities of MCC-related adsorbents were OP-OH-P (151.81 mg/g) > OP-OH-SH (150.80 mg/g) > OP-OH-H-25 (124.90 mg/g) > > OP-OH-NH2 (55.23 mg/g). OP-OH-P exhibited the strongest Cd(II) sorption ability under the interference of mixed aquatic components. The intrinsic Cd(II) sorption mechanisms were identified as inner-sphere complexation and cation-π bond interaction. Overall, the select priority of modifying agents is orthophosphoric acid > mercaptoacetic acid > > glycine when preparing functionalized MCC adsorbents for purifying Cd(II)-polluted water systems.

P‐Toluene Sulphonic Acid (PTSA): An Efficient Catalyst for One‐Pot Three‐Component Synthesis of Novel 3‐Pyrazolyl‐Thiazolidin‐4‐One Derivatives

AbstractThis research article focuses on the pathway for metal‐free unprecedented one‐pot three‐component synthesis of biologically active 3‐pyrazolyl‐thiazolidin‐4‐one derivatives through cyclo‐condensation of aromatic aldehydes, 1H‐pyrazol‐3‐amine and thioglycolic acid in aqueous medium. p‐Toluene sulphonic acid (PTSA), a non‐toxic, cheaper, easily accessible, eco‐benign, organic acid‐catalyst was explored to mediate this reaction. Formation of novel 3‐pyrazolyl‐thiazolidin‐4‐one derivatives, environment‐benign conditions, quick reaction time, excellent functional group acceptance and moderate to high yield of the products are some of the chief advantages of the reaction. Further, this methodology will surely contribute in various fields of synthetic organic methodology, pharmaceutical industry and natural bio‐active product synthesis.

Quantitative analysis of loxoprofen sodium loaded microspheres comprising pectin and its thiolated conjugates: In-vivo evaluation of their sustained release behavior

Continuous use of oral NSAIDs can damage mucosal membrane, which results in decreased bioavailability and non-compliance with the therapy. But the use of sustained release drug delivery systems might offer a solution. Objective was to synthesize mucoadhesive SR microspheres by using different combinations of pectin (PEC) and its thiolated derivative (T-PEC3100) for improved loxoprofen (LS) permeation. Thiolated pectin (T-PEC) was synthesized by the esterification method using thioglycolic acid. Thiolation was confirmed by thiol group quantification and charring point determination. Further characterization was done by Fourier Transform Infrared spectroscopy (FTIR), and Scanning electron microscopy (SEM). Ex-vivo mucoadhesion study was performed to confirm the improved characteristics. Microspheres (MS) were prepared using different ratios of PEC/T-PEC by solvent evaporation method and their particle size and surface morphology were evaluated. Mucus permeation study was carried out using the trans-well plate method. Sustained release behavior of prepared microspheres was investigated through the edema inhibition method in albino rats. T-PEC3100 was considered the optimum formulation for further evaluation and contained maximum thiol group content. FTIR spectra showed a characteristic peak of –SH and charring point was also changed considerably confirming the successful thiolation of PEC. SEM results showed spherical microspheres in the size range of 2–10 μm. Thiol-rich formulation of MS exhibited more than 80 % release after 12 h and maximum absorbable dose (MAD) was calculated as 400 μg % inhibition of edema in MS treated group was slowly attained initially but the reduction in inflammation was detected even after 24 h as compared to control group. Promising results from In-vivo edema inhibition study suggest the possible use of these thiolated MS in formulating sustained release formulation for arthritis.

Realizing efficient near-infrared emission in Cu-In-S/ZnS quantum dots: Aqueous synthesis, optical properties and applications

Ternary I-III-VI quantum dots (QDs) are promising substitutions to Pb and Cd chalcogenide QDs in various applications such as LED, biodetection and sensing. It is urgent to explore near-infrared (NIR) emitting QDs with the advantages of low-cost synthesis and nontoxicity. Herein, water-soluble NIR Cu-In-S/ZnS (CIS/ZnS) QDs were obtained utilizing thioglycolic acid (TGA) and polyethyleneimine (PEI) as the stabilizing molecules in a commercial pressure cooker. Moreover, we detailedly investigated the influence factors on the PL property of CIS QDs and CIS/ZnS QDs including species of sulfur source, reaction time, pH, the dosage of TGA, PEI, Na2S, number of ZnS coating layers and the molar ratio of Cu/In. These QDs with adjusting Cu/In ratios show the emission maximum in the range of 710–750 nm. The maximum PL quantum yield (PLQY) of 20 % was acquired for CIS/ZnS QDs with a Cu/In ratio was 0.33/1 and three ZnS layer coating. Finally, we fabricated a NIR pc-LED lamp by using blue LED chips and CIS/ZnS QDs. The device shows a broadband NIR emission centered at 770 nm, which can be applied in night-vision system.

Highly fluorescent CdTe/ZnSe quantum dot-based “turn-off” sensor for the on-site rapid detection of Lead ions in aqueous medium

Lead (Pb) is a heavy metal known for its adverse effects on both human health and the environment. In recent years, the industrial utilization of Pb2+ has surged, underscoring the imperative need for efficient measurement methods. In this study, a rapid and simple photochemical method was used to synthesize thioglycolic acid (TGA)-stabilized CdTe/ZnSe core-shell quantum dots (QDs). These CdTe/ZnSe QDs emit vibrant green fluorescence and exhibit remarkable quenching in the presence of Pb2+ ions. This property enables the development of an on-site on/off sensor without the necessity of additional modifications. The proposed sensor possesses an outstanding sensitivity to Pb2+, with a detection limit and linear range of 31.8 nM and 50 nM–10 µM, respectively. Importantly, the selectivity of this fluorescence-based sensor was validated by analyzing various positively and negatively charged ions. Furthermore, the developed sensor showed reliable performance against real river, agricultural, and tap water, as confirmed by Inductively Coupled Plasma (ICP) analysis. Additionally, CdTe/ZnSe QDs immobilized on glass slides were successfully employed for on-site water sample analysis, providing a versatile solution for environmental monitoring.