Thiosalicylic Acid Research Articles

Complexes of copper(II) with tetradentate S,O-ligands: Synthesis, characterization, DNA/albumin interactions, molecular docking simulations and antitumor activity

Four new complexes of copper(II) with S,O-tetradentate ligands, derivatives of thiosalicylic acid, encompassing an ethylene-, propylene-, butylene- and pentylene- bridge, were synthesized and characterized by microanalysis, molecular conductance and infrared (IR) spectra. The structures were assumed based on the previously mentioned analyses and confirmed with the results of electron paramagnetic resonance (EPR) spectra. The reactivity of complexes towards L-methionine (L-Met), L-cysteine (L-Cys) and guanosine-5′-monophosphate (5’-GMP) was also examined. Complex C1 ([Cu(S,O-ethylene-thiosalicylic acid)(H2O)2]) containing two inert methylene groups in the side chain of ligand shows the highest reactivity, while the least reactive is complex C4 ([Cu(S,O-pentylene-thiosalicylic acid)(H2O)2]) with five methylene groups. All complexes showed the highest reactivity towards L-Met and the lowest reactivity towards 5’-GMP. The interactions of complexes C1-C4 with calf thymus DNA (ct-DNA) were examined by ultraviolet-visible (UV–Vis) absorption and fluorescence spectral studies, revealing good DNA interaction abilities. All synthesized complexes C1-C4 show to interact with human serum albumin (HSA) with high values of binding constants. Complexes interaction with DNA/HSA was also confirmed using molecular docking simulations. All synthesized complexes reduce viability of human colon, breast and lung cancer cells, evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) colorimetric technique. The complex [Cu(S,O-pentylene- thiosalicylic acid)(H2O)2] showed the highest binding affinity constants to DNA/HSA and highest cytotoxicity, thus presenting a good candidate for further pharmacological research in the field of colon, breast and lung cancer therapy.

Glow and Flash Adjustable Chemiluminescence with Tunable Waveband from the Same CuInS2@ZnS Nanocrystal Luminophore.

All commercial chemiluminescence (CL) assays are conducted with either glow or flash CL of eye-visible waveband from chemical luminophores. Herein, glow and flash, as well as waveband adjustable CL from the same nanoparticle luminophore of thiol-capped CuInS2@ZnS nanocrystals (CIS@ZnS-Thiol), are proposed via extensively exploiting the differed redox nature of CL triggering reagents. Taking thiosalicylic acid (TSA) as the model thiol-capping agent, the electron-injection-initiated charge transfer between CIS@ZnS-TSA and reductant can bring out efficient glow CL while the hole-injection-initiated charge transfer between CIS@ZnS-TSA and oxidant can give off obvious flash CL under optimum conditions. The maximum emission wavelength for CL of CIS@ZnS-TSA is adjustable from 730 nm to 823 nm via employing different triggering agents. Promisingly, the coexistent reductant of N2H4·H2O and oxidant of H2O2 can be employed as dual triggering reagents to trigger eye-visible and highly efficient flash CL from CIS@ZnS-TSA. The maximum emission intensity for flash CL of CIS@ZnS-TSA/N2H4-H2O2 is 101-fold greater than the glow CL of CIS@ZnS-TSA/N2H4 and 22-fold greater than the flash CL of CIS@ZnS-TSA/H2O2, respectively. The flash CL from CIS@ZnS-TSA/N2H4-H2O2 is qualified for highly sensitive and selective CL immunoassay in a commercialized typical procedure with the entire operating process manually terminated within 35 min.

Advancing the Development of Recyclable Aromatic Polyesters by Functionalization and Stereocomplexation.

The development of innovative synthetic polymer systems to overcome the trade-offs between the polymer's depolymerizability and performance properties is in high demand for advanced material applications and sustainable development. In this contribution, we prepared a class of aromatic cyclic esters (M1-M5) from thiosalicylic acid and epoxides by facile one-pot synthesis. Ring-opening polymerization of Ms afforded aromatic polyesters P(M)s with high molecular weights and narrow dispersities. The physical and mechanical properties of P(M)s can be modulated by stereocomplexation and regulation of the side-chain flexibility of the polymers, ultimately achieving high-performance properties such as high thermal stability and crystallinity (Tm up to 209 °C), as well as polyolefin-like high mechanical strength, ductility, and toughness. Furthermore, the functionalizable moieties of P(M)s have driven a wide array of post-polymerization modifications toward access to value-added materials. More importantly, the P(M)s were able to selectively depolymerize into monomers in excellent yields, thus establishing its circular life cycle.

Advancing the Development of Recyclable Aromatic Polyesters by Functionalization and Stereocomplexation

AbstractThe development of innovative synthetic polymer systems to overcome the trade‐offs between the polymer's depolymerizability and performance properties is in high demand for advanced material applications and sustainable development. In this contribution, we prepared a class of aromatic cyclic esters (M1–M5) from thiosalicylic acid and epoxides by facile one‐pot synthesis. Ring‐opening polymerization of Ms afforded aromatic polyesters P(M)s with high molecular weights and narrow dispersities. The physical and mechanical properties of P(M)s can be modulated by stereocomplexation and regulation of the side‐chain flexibility of the polymers, ultimately achieving high‐performance properties such as high thermal stability and crystallinity (Tm up to 209 °C), as well as polyolefin‐like high mechanical strength, ductility, and toughness. Furthermore, the functionalizable moieties of P(M)s have driven a wide array of post‐polymerization modifications toward access to value‐added materials. More importantly, the P(M)s were able to selectively depolymerize into monomers in excellent yields, thus establishing its circular life cycle.

Alliance between doping Ag and dual ligands-enhanced fluorescent gold nanoclusters for the assays of vitamin B12 and chlortetracycline hydrochloride

A stable, water-soluble, heightened quantum yields (QYs) Au nanoclusters by the alliance between doping Ag and dual ligands (thiosalicylic acid and bovine serum albumin) (TSA/BSA-Au/AgNCs) was prepared using one-step wet chemical synthesis. The effect of different types of aromatic thiols and the molar ratio of Au-Ag on the photo-luminescence performance of AuNCs was discussed in detail. The alloy NCs is shown to be viable fluorescent method for vitamin B12 (VB12) and chlortetracycline hydrochloride (CCH) assays, and become an excellent temperature sensor in the range of 10–50 °C. The fluorescence (FL) of TSA/BSA-Au/AgNCs was quenched with the addition of VB12 or CCH coming from Förster resonance energy transfer (FRET) combined with inner filter effect (IFE). The method can detect VB12/CCH by fluorometry with a linear response in the range of 0.33–60.0/0.33–60.0 μmol·L−1 and a 71.0/64.0 nmol·L−1 detection limit (at 3σ/slope). Furthermore, the proposed method was extended to the assays of VB12 in mineral water or tablets and CCH in veterinary drug or ointment with satisfactory results.

Effect of foliar application of bioregulators for improving high temperature tolerance of wheat (Triticum aestivum L.)

Aim: The aim of the present study was to evaluate the effect of sowing at different thermal environments and its interaction with foliar spray of bio-regulators on yield and yield contributing traits in wheat. Methodology: The present study was conducted by using split plot design with four replications consisting of 24 treatments, namely, main plots: three sowing at different thermal environments (22oC, 20oC and 18oC) and sub plots: eight foliar spray of bioregulators (control, water spray, salicylic acid @ 100 ppm, salicylic acid @ 200 ppm, thio salicylic acid @ 100 ppm, thio salicylic acid @ 200 ppm, thioglycolic acid @ 100 ppm and thioglycolic acid @ 200 ppm). Results: The results indicated that sowing at 20oC recorded the maximum yield parameters viz, effective tillers/m row length, length of ear, no. of grains per ear, test weight, days to maturity and grain, straw and biological yield of wheat over sowing at 22oC and 18oC temperature. Sowing at different thermal environment treatments was found to be non-significant with harvest index of wheat. Among the foliar spray of bioregulators, the treatment B4 (SA @ 200 ppm) significantly increased the yield components and yield, while remaining at par with B6 (TSA @ 200 ppm) and B8 (TGA @ 200 ppm) proved superior in comparison to rest of the treatments. However, the significantly higher harvest index was obtained under B4 (SA @ 200 ppm) treatment and was statistically at par with all other treatments, except B1 and B2. Interpretation: It is concluded that salicylic acid @ 200 ppm at tillering (40-45 DAS) and ear emergence (60-65 DAS) stage may be sprayed on 20oC temperature sown crop is a viable option to improve wheat yield under semi-arid environment.

In Situ Growth Large Area Silver Nanostructure on Metal Phenolic Network Coated NAAO Film and Its SERS Sensing Application for Monofluoroacetic Acid.

Rapid screening monofluoroacetic acid (FAcOH) is responsible for preventing chemical poisoning and food safety events. Whereas surface enhanced Raman scattering (SERS) spectra is an effective tool for detecting forbidden chemicals, it is difficult to directly detect FAcOH due to its small Raman scattering cross section as well as weak adsorption on SERS substrates. In this work, the metal phenolic supramolecular networks (MPNs, i.e., the tannic acid and Fe3+ complex) were fabricated on the commercial nanoanodic aluminum oxide film (NAAO) for assisting in situ chemical deposition highly uniform Ag nanostructure over large areas (the NAAO@AgNS). The low cost and simple fabrication process made the NAAO@AgNS a single-use consumable. For FAcOH detection, a specific derivative reaction between FAcOH and thiosalicylic acid (TSA) was introduced. By taking TSA as the Raman probe, its SERS signal attenuated constantly with the increasing amount of FAcOH. For improving quantitative accuracy, thiocyanate (SCN-) was introduced on the NAAO@AgNS as an internal standard; thus, the characteristic peak intensity ratios associated with TSA and SCN- (I1035/I2125) were fitted to the concentration of FAcOH. It was demonstrated that the SERS assay achieved good sensitivity and selection toward FAcOH with the limit of quantitation (LOD) as low as 50 nmol L-1. The NAAO@AgNS featured with highly sensitive, uniform, and consistent SERS performances could easily extend to wide SERS applications.

Effect of Nobel Metal Ions on the Synthesis of Metal Nanoclusters for Selective Detection of Various Heavy Metals

In this study, effect of noble metal ion (Au, Ag and Cu) on the synthesis of metal nanoclusters (MNCs) has been investigated. Through heating at 70ºC, TSA/BSA-Au, -Ag and -Cu NCs were separately prepared from Au3+, Ag+, and Cu2+in the presence of bovine serum albumin (BSA) and thiosalicylic acid (TSA). They exhibit photoluminescence (PL) at 700, 624 and 430 nm, with average life times of 1500, 100 and 11.71 ns, respectively, when excited at 350 nm. X–ray photoelectron spectroscopy (XPS) data support the presence of metal core (M0) and metal–thiolate shell (Mn–SRm), each in the TSA/BSA-MNCs. Spectroscopic measurements reveal the formation of Au32–SR, Ag9–SR and (Cu4–Cu13)–SR species separately in the TSA/BSA-Au, -Ag and -Cu NCs. Through PL quenching of the TSA/BSA-Au, -Ag and -Cu NCs, they have been used separately for quantitation of Hg2+, As3+and Cr6+ , with linear ranges of 10-400, 4-18, and 40-400 nM and limits of detection (LODs) of 0.25, 2.34 and 3.54 nM, respectively. The PL quenching is mainly due to aggregation of the MNCs through metallophilic or metal–thiol complexation. The stable TSA/BSA–Au, -Ag and -Cu NCs have been employed separately for the determination of the concentrations of Hg2+, As3+and Cr6+ions in the spiked sea water samples, showing advantages of simplicity, rapidity, high selectivity, and sensitivity.

Frost management in mustard under climate change scenario in semi arid ecosystem of Rajasthan

Among various factors, in recent years climate change becomes a major challenge for the food security of the country. Extreme events such as frost, heat stress, moisture stress, new diseases, pests & weeds become a major hindrance in successful crop production. Frost (Pala, Tusar or daha in Hindi) is a localized phenomenon, which is fairly common in northern India. Due to Climate change frost becomes a regular phenomenon in recent years in semi arid regions of Rajasthan. The predominantly grown mustard (Brassica juncea L.) is highly susceptible to frost injury. Mustard crop suffers badly due to the attack of frost in 2006, 2008, 2010, 2011, 2012, 2013& 2014 in Rajasthan. An experiment was conducted during Rabi seasons (2011-12 to 2013-14) at Research form RARI Durgapura on sandy loam soil. Application of thiourea @ 500 ppm, wettable sulphur @ 0.2%), thiosalicylic acid @100 ppm, salicylic acid @100 ppm and H2SO4@0.1% being at par significantly increased seed and stover yield of mustard and recorded the lowest yield losses. The maximum net returns (Rs 38019/ha) along with the highest B:C ratio (2.61) was accrued due to application of thiourea followed by thiosalicylic acid and wettable sulphur. The Spray of thiourea (500 ppm), wettable sulphur (0.2%) or thio-salicylic acid (100 ppm) or salicylic acid (100 ppm) at pre flowering and seed formation stage was found to be effective in mitigating the adverse impact of frost in mustard. This study may help to understand and select suitable treatments to reduce frost impact on growing mustard in environmental conditions under semi-arid zone of India.

Inhibition of ERAD synergizes with FTS to eradicate pancreatic cancer cells

BackgroundPancreatic ductal adenocarcinoma (PDAC), one of the most lethal cancers, is driven by oncogenic KRAS mutations. Farnesyl thiosalicylic acid (FTS), also known as salirasib, is a RAS inhibitor that selectively dislodges active RAS proteins from cell membrane, inhibiting downstream signaling. FTS has demonstrated limited therapeutic efficacy in PDAC patients despite being well tolerated.MethodsTo improve the efficacy of FTS in PDAC, we performed a genome-wide CRISPR synthetic lethality screen to identify genetic targets that synergize with FTS treatment. Among the top candidates, multiple genes in the endoplasmic reticulum-associated protein degradation (ERAD) pathway were identified. The role of ERAD inhibition in enhancing the therapeutic efficacy of FTS was further investigated in pancreatic cancer cells using pharmaceutical and genetic approaches.ResultsIn murine and human PDAC cells, FTS induced unfolded protein response (UPR), which was further augmented upon treatment with a chemical inhibitor of ERAD, Eeyarestatin I (EerI). Combined treatment with FTS and EerI significantly upregulated the expression of UPR marker genes and induced apoptosis in pancreatic cancer cells. Furthermore, CRISPR-based genetic ablation of the key ERAD components, HRD1 and SEL1L, sensitized PDAC cells to FTS treatment.ConclusionOur study reveals a critical role for ERAD in therapeutic response of FTS and points to the modulation of UPR as a novel approach to improve the efficacy of FTS in PDAC treatment.

ES28.01 Biology of KRAS Targeting Agents

ES28.01 Biology of KRAS Targeting Agents

Immobilized Thiosalicylic Ligand System Potentials for the Detoxification of Some Heavy Metals from Tannery Wastewater

Polysiloxanes are characterized by silicon and oxygen backbone and are hydrophobic in nature with low moisture uptake widely used for medical applications. Polysiloxane immobilized thiosalicylic acid ligand system has been prepared through sol-gel method, gelation was observed after 40 minutes. The immobilized ligand was characterized using FTIR, the spectrum showed characteristic absorption bands (cm^-1) at: 3377 (OH), 2981 (C-H stretch); 2631 (SH); 1587 to 1684 (C=C, C=O); 1032 to 1144 (Si - O) respectively. SEM analysis showed irregular particle sizes of the polysiloxane matrices while EDX elemental composition gave (wt %): 3-CPPS; Si (50.45), O (25.02) and Cl (24.57). F - 3CPPS showed, O (58.68), Si (41.32); thiosalicylic (7.14 of S). The extraction of metal ions (Cr³⁺, Fe³⁺, Pb²⁺, Cu²⁺ and Zn²⁺) were studied using Microwave Plasma Atomic Emission Spectrophotometer (Agilent MPAES-4200) at pH 6.0. Thermodynamic range with respect to Cr³⁺, Fe³⁺, Pb²⁺, Cu²⁺ and Zn²⁺ yielded negative values forΔG^o: Cu²⁺-(11.483 to 14.842) to Zn²⁺ -(14.368 to 14.842)KJmol^-1; positive values for ΔH^o: Fe³⁺ (0.000) to Pb²⁺ (105.130)KJmol^-1 and ΔS^o: Zn²⁺ (47.421) to Pb²⁺ (389.328)Jmol¹K¹ respectively, indicating spontaneous, endothermic reactions and high degree of disorderliness with respect to metal ion binding capacity to the ligand system.

PARAFAC and MCR-ALS approaches to the pKa determination of benzoic acid and its derivatives

In general, the identification of biological activities of a molecule requires the observation of its physicochemical characteristics with its molecular interactions in an organism. The acid-base ionization constant (or pKa) is one of the key parameters that shows the physicochemical behaviors of molecules used in pharmaceuticals, foods, cosmetics etc. Therefore, the development of new methods (or approaches) is necessary to get simple, rapid, inexpensive and reliable determination of the acidity constants of active and inactive ingredients used in commercial products. In this paper, new UV spectroscopic methods were developed for the first time, by applying parallel factor analysis (PARAFAC) and multivariate curve resolution-alternating least squares (MCR-ALS) to the pH-UV spectral data arrays for determining the pKa values of benzoic acid and its five derivatives (4-fluorobenzoic acid, thiosalicylic acid, anthranilic acid, phthalic acid, 4-aminobenzoic acid). The pH profiles obtained by the PARAFAC and MCR-ALS decomposition of the pH-UV data arrays were used for the quantitative estimation of the acid-base ionization constants for the investigated compounds without classical titration procedure. We concluded that the proposed PARAFAC and MCR-ALS provided us an opportunity for simple and rapid pKa determination of relevant compounds, which have functional importance in pharmaceutical and food industries.

Efficient removal of Pb(II) from water using silica gel functionalized with thiosalicylic acid: Response surface methodology for optimization

The adsorption of Pb(II) onto silica gel functionalized with thiosalicylic acid (TSA@)amine modified SiO2) was studied at 300, 305, 310 and 315 K. The effects of independent variables (pH, adsorbent dose and initial concentration of Pb(II)) on the removal of Pb(II) from water were evaluated and response surface methodology was applied to optimize them. Under the optimized conditions (pH: 6; adsorbent dose, 0.20 g/20 mL and initial concentration: 50 mg/L), removal efficiency of Pb(II) was 98.78%. The adsorption equilibrium data obtained from batch experiments were examined by various isotherm models. Freundlich isotherm model fitted well to the experimental data and indicating the multilayer coverage of Pb(II) on the heterogeneous surface of TSA@)amine modified SiO2. Adsorption kinetic data were investigated by surface and diffusion based kinetic models. Kinetic data fitted well to pseudo-second order model with R2 > 0.999. Elovich model with R2 > 0.999 revealed the occurrence of chemical reaction between Pb(II) and active sites of TSA@)amine modified SiO2. Thermodynamic parameters suggested the spontaneous and endothermic nature of Pb(II) adsorption onto TSA@)amine modified SiO2.

Synthesis and Characterization of Immobilized Thiolactic Ligand System for the Detoxification of Tannery Wastewater

A porous solid polysiloxane immobilized thiosalicylic acid ligand system has been prepared by hydrolytic polycondensation of tetraethylorthosilicate with a mixture of 3-chloropropyltrimethoxysilane, methanol and sodium hydroxide as a catalyst, gelation formed after 40 min. The product formed was functionalized with excess ethylchloroacetate, triethylamine and immobilized with thiosalicylic acid. The immobilized ligand was characterized using FTIR, the spectrum showed characteristic absorption regions (cm-1) at: 3384 (OH), 1587 to 1722 (C=C, C=O); 900 to 1038 (Si - O) respectively. SEM-EDX showed irregular particle sizes of the polysiloxane matrices with elemental composition (wt %): 3-CPPS; Si (50.45), O (25.02) and Cl (24.57). F - 3CPPS showed, O (58.68), Si (41.32); thiolactic (0.00 of S). The competitive sorption characteristic of the metal ions (Cr3+, Fe3+, Pb2+, Cu2+ and Zn2+) were studied using Microwave Plasma Atomic Emission Spectrophotometer (Agilent MPAES-4200). The immobilized thiolactic ligand exhibits high potential for the extraction of heavy metals in tannery wastewater at pH 6.0, this development would improve the treatment of tannery wastewater at a low cost; batch or column systems of extraction of metal could be employed. Thermodynamic range for the parameters with respect to Cr3+, Fe3+, Pb2+, Cu2+ and Zn2+ yielded negative values for ΔGo, (Cu2+ -(8.650 to 11.962) to Fe2+ -(14.368 to 14.842) KJmol-1; positive values for ΔHo: Zn2+ (0.000) to Cu2+ (21.047) KJmol-1 and ΔSo: Zn2+ (47.421) to Fe3+ (245.869) Jmol1K1 respectively, indicating spontaneous, endothermic reactions and high degree of disorderliness with respect to metal ion binding capacity to the ligand system.

Hierarchical clusters of lanthanide cluster plus gold cluster

In this work, we provide a facile and valid one-pot synthesis method to create unreported hierarchical cluster of lanthanide cluster plus gold cluster (Ln-Au cluster), by introducing the ligands with bifunctional groups of carboxyl and sulfhydryl. The identities of Ln-Au clusters are fully characterized to be Ln7Au20 (MPCA)21 (Ln = Ce, 1; Eu, 2; Tb, 3; MPCA = 2-mercaptonicotinic acid) and Ln5Au18(TSA)15 (Ln = Ce, 4; Eu, 5; Tb, 6; TSA = thiosalicylic acid). Results reveal the six Ln-Au clusters are hierarchical structure that Ln cluster and Au cluster are connected by bifunctional ligands of MPCA or TSA. The excellent “antenna effect” of TSA results in highly luminescence quantum yield of 67% for 6. Interestingly, Ln-Au clusters 4 and 5 show very high MB adsorption capacity of 189 and 158 mg/g in short adsorption equilibrium time of 30 and 5 min, respectively.

Photoluminescent nanoprobes based on thiols capped CdTe quantum dots for direct determination of thimerosal in vaccines

CdTe quantum dots (CdTe QD) have been produced at different times of synthesis (1, 2, and 4 h) using thiols as capping agents: mercaptopropionic acid (MPA), mercaptosuccinic acid (MSA) and N-acetyl-l-cysteine (NAC) using water as a solvent. The produced CdTe QD were characterized by UV–vis and photoluminescence (PL) spectroscopy and showed a relationship among reflux time, size, and spectroscopic properties. CdTe QD were shown to interact with thimerosal (TM), an organic mercury compound, and the PL intensity was effectively quenched, characterizing an ON-OFF process. However, the NAC capped CdTe (CdTe-NAC) at 1 h presented the best sensitivity for TM determination. Under optimized conditions, a linear range from 0.1 to 1.0 μg mL−1 (0.25–2.5 μM) and a LOD of 26.6 μg L−1 (66.7 nM) were achieved. The influence of different mercuric species [Hg(II), methylmercury, ethylmercury, and phenylmercury], along with thiosalicylic acid (TSA), and other ionic species on the sensitivity of the method and the interaction mechanism between TM and CdTe-NAC have been discussed. The method was successfully applied for direct quantification of TM in vaccines, and the results were validated by cold vapor atomic fluorescence spectroscopy (CV AFS). Finally, the proposed method proved to be fast, sensitive, and simple for suitable use in vaccine quality control.

Facile synthesis of thiosalicylic acid functionalized silica gel for effective removal of Cr(III): Equilibrium modeling, kinetic and thermodynamic studies

Thiosalicylic acid functionalized silica gel (SiO2-APS-TSA) was prepared after modification of silica with 3-aminopropyltrimethoxysilane. The adsorption of Cr (III) onto SiO2-APS-TSA was carried out in batch experiments and result shows high removal efficiency (99.90 %) of Cr (III). The characterization of SiO2-APS-TSA was done using FTIR, TGA, DTA, and SEM with EDX. The adsorption of Cr (III) onto SiO2-APS-TSA was optimized by response surface methodology. Central composite design of three factors was undertaken to examine the process parameters, namely pH (0.64–7.36), adsorbent dose (15.0–385.0 mg) and contact time (9.55–110.45 min). The goodness of fit of the experimental data to the second-order polynomial model was revealed with R2 of 0.9999. The results showed that 0.2 g of SiO2-APS-TSA was sufficient to remove 99.90 % Cr (III) from aqueous solution (20 mL; 20 mg L−1) at pH 4.0 in 60 min. Linear and nonlinear fitting of Freundlich isotherm model to adsorption data revealed the multilayer coverage of Cr (III) onto SiO2-APS-TSA. Pseudo second order kinetic model fitted well to the kinetic data. Negative values of ΔG° suggested the spontaneity of the adsorption of Cr (III). The sorption/desorption study demonstrated the potential of SiO2-APS-TSA as an adsorbent to remove Cr (III) from wastewater.

Nanostructured Ba/ZnO modified electrode as a sensor material for detection of organosulfur thiosalicylic acid

Electrochemical sensors are regulated by the interaction of several chemical solutions to generate an electrical signal proportional to the concentration of the analytes. A novel electrochemical sensor is reported in this study for an organosulfur molecule, thiosalicylic acid (TSA) detection by the casting of electro-catalytic barium doped zinc oxide nanoparticle suspension on a glassy carbon electrode (GCE). The electrochemical response of TSA was examined simultaneously for bare GCE and electro-chemically modified GCE, i.e. Barium doped zinc oxide nanoparticle/GCE (BDZONPs/GCE) by utilizing different voltammetric techniques in an acidic medium of pH 3.0. In comparison with the bare GCE, the modified GCE exhibits a decent response towards oxidation of TSA with a well-defined peak current. The catalytic nature, conducting nature, and large surface area of the nanoparticles which influences the remarkable enhancement of the TSA at BDZONPs/GCE was examined. The impact of accumulation time, pH dependency, and the scan rate variation were also studied. Based on the experimental data the physicochemical parameters were being calculated. The sensitive squarewave voltammetry (SWV) was used to monitor the low detection limit of TSA. Applicability of proposed work showed good sensitivity, selectivity, and noticeable recovery results with BDZONPs/GCE.

Biosorption Characteristics of Cu(II) and Cd(II) Ions by Modified Alginate

In this study, a novel biosorbent was prepared by the modification of sodium alginate with thiosalicylic acid in the presence of calcium ions (TS-A). TS-A was then characterized and its removal performance for Cu(II) and Cd(II) ions from the aqueous solutions was investigated. The effects of batch and column parameters on the biosorption were systematically investigated. The obtained data from the biosorption results were well fitted by the pseudo-second-order kinetic and Langmuir isotherm models. The maximum biosorption capacities of TS-A were found as 426.9 mg g−1 for Cu(II) ions and 592.9 mg g−1 for Cd(II) ions. In the column system, the saturation points of TS-A were obtained as 180 min and 150 min for Cu(II) and Cd(II) ions, respectively. In conclusion, TS-A has provided the removal of heavy metal ions with superior performance by a smart biosorption method, offering advantages such as rapid kinetic and high biosorption capacities.