Publications by authors named "Pandiyan Thangarasu"
Our research on the chromium complex of macrocyclic ligands as a precursor for nitric oxide release makes a significant contribution to the field of chemistry. We conduct a detailed analysis of nitrito chromium complexes, specifically trans-[M(III)L(ONO)], where M=Cr(III) and L-L represent different ligands such as L=1,4,8,11-tetraazacyclotetradecane, L= (5,7-dimethyl-6-benzylcyclam), L= (5,7-dimethyl-6-anthracylcyclam), L= (5,7-dimethyl-6-(p-hydroxymethylbenzyl)-1,4, 8,11-cyclam) and L= (5,7-dimethyl-6-(1¢-methyl-4'-(1"-carboxymethylpyrene) benzyl)-1,4,8,11-tetraazacyclotetradecane). Our objective is to comprehensively understand the mechanism of NO release and identify the key factors influencing NO delivery.
View Article and Find Full Text PDFArticle Synopsis
- Researchers created and characterized ZnO nanoparticles, which were then combined with a chemical compound (salen) to detect metal ions in water.
- The ZnO-salen system was found to selectively identify aluminum ions, and the presence of potassium further increased its fluorescence signal.
- This detection method was successfully applied in human glioblastoma U251 cells, demonstrating high cell viability even at higher concentrations of ZnO-salen.
Article Synopsis
- - The study focused on creating photocatalysts from steel waste by oxidizing them using various pH levels and temperatures, achieving high production efficiency and magnetic properties.
- - The resulting materials, particularly (Co-Zn)FeO, exhibit a bandgap of 2.02 eV, allowing them to be activated by sunlight and showing uniform particle sizes.
- - When applied to treat black liquors from cellulose extraction, the photocatalysts led to a 15% reduction in Chemical Oxygen Demand and improved biodegradability, demonstrating potential for large-scale environmental applications.
Simultaneous recognition of dopamine and uric acid in real samples through highly sensitive new electrode fabricated using ZnO/carbon quantum dots: bio-imaging and theoretical studies.
Eduardo D Tecuapa-Flores Cristian B Palacios-Cabrera Alan J Santiago-Cuevas José G Hernández Jayanthi Narayanan Pandiyan Thangarasu
Analyst
December 2023
Article Synopsis
- The study explores the use of modified graphite carbon paste electrodes incorporating ZnO/carbon quantum dots for the electrochemical detection of dopamine (DA) and uric acid (UA), crucial metabolites in human health.
- The electrodes were extensively characterized through various analytical techniques and demonstrated high sensitivity in detecting DA, even at low concentrations, without interference from UA.
- The ZnO/CQD electrodes successfully detected both DA and UA simultaneously in human urine samples, showcasing a significant potential for real-world applications in monitoring these metabolites.
Article Synopsis
- Researchers developed a new material called SiO@TiO that has a raspberry-like structure, aimed at lowering the band gap of titania using functionalized graphene oxide as support.
- Various analytical techniques, including FTIR, XRD, SEM, TEM, and HR-TEM, were used to characterize the material.
- The band gap was analyzed through UV-Vis absorption spectra and calculated using the Kubelka-Munk equation, accompanied by a theoretical study on the interaction between the components.
Article Synopsis
- The paper discusses the growing importance of capturing and storing carbon dioxide (CO2) to reduce greenhouse gas emissions, focusing on doping cations like Li, Mg, and Co on ZrO to enhance CO2 adsorption.
- The samples were prepared using the sol-gel method, and their crystallographic changes were analyzed, revealing transformations in crystal phases and consistent thermal stability with varying atomic sizes.
- Experimental results showed that CoZrO has a high efficiency in capturing CO2 (up to 75%) and that the interaction dynamics with CO are affected by temperature, supporting the theoretical findings of greater feasibility for MgZrO and CoZrO compared to LiZrO.
Article Synopsis
- - The study focuses on converting plastic waste into fluorescent carbon dots (CDs) by using a sustainable carbonization process and then enhancing their functionality with L-cysteine and o-phenylenediamine for metal ion detection.
- - Various analytical techniques, like X-ray diffraction and electron microscopy, were used to characterize these CDs, which successfully detect toxic metal ions like Cu, Fe, and Hg at low concentrations, while also aiding in the detection of histamine.
- - Additionally, the research involved using these CDs for cellular imaging in yeast cells and included theoretical studies to confirm the structure and spectral properties of CDs, aligning experimental results with computational predictions.
Article Synopsis
- - The study presents an easy and eco-friendly technique to create azo oligomers from inexpensive compounds like nitroaniline using nanometric FeO spheres coated with various metallic nanoparticles (Cu, Ag, Au).
- - The efficient reduction process achieved a high conversion rate of approximately 97%, with FeO-Au acting as the most effective catalyst—20 times faster than unmodified FeO.
- - Product analysis via HPLC-MS confirmed the successful formation of azo oligomers through N=N bonding, with a six-unit oligomer being the primary product formed and reaction dynamics supported by computational studies.
Effect of the structural integrity on the size and porosity of gold-implanted mixed-metal oxide nanocomposites: their influence on the photocatalytic degradation of thioanisole.
Alan Javier Santiago Cuevas Cristian Brayan Palacios Cabrera Carlos Alberto Huerta Aguilar Itzia Irene Padilla-Martínez Pandiyan Thangarasu
Dalton Trans
November 2022
Article Synopsis
- This study examines how the binding strength and structural integrity at the interface between metal ions and host materials affect the properties of nanocomposites, specifically those made with gold nanoparticles.
- Two types of matrices, CeO-ZrO and CeO-AlO, were created and analyzed using various methods to understand their structural and electronic characteristics.
- Results showed that gold embeds better in the CeO-ZrO matrix than in CeO-AlO, leading to smaller particle sizes and enhanced electronic properties, such as a lower band gap and improved electron transfer in the former.
Article Synopsis
- The study investigates the effect of adding silver nanoparticles (Ag NPs) to zinc iron oxide (ZnFeO) nanoparticles on the photodegradation of Rhodamine B dye, highlighting the presence of multiple crystalline interphases in the composite.
- Magnetic properties improved significantly with the addition of Ag NPs, where ZnFeO-Ag showed a drastic increase in magnetic saturation at low temperatures compared to the unmodified ZnFeO and FeO.
- The composite demonstrated enhanced quantum yield for photodegradation, with the optimal performance seen in ZnFeO-Ag at concentrations between 1.5% and 2.5%, while also exhibiting antibacterial activity due to the combined effects
Rapid electrochemical recognition of trimethoprim in human urine samples using new modified electrodes (CPE/Ag/Au NPs) analysing tunable electrode properties: experimental and theoretical studies.
Eduardo D Tecuapa-Flores José Guadalupe Hernández Pedro Roquero-Tejeda Jesús A Arenas-Alatorre Pandiyan Thangarasu
Analyst
December 2021
Article Synopsis
- Pharmaceutical effluents pose significant environmental challenges, and electrochemical processes, particularly with new carbon paste electrodes (CPEs) using gold and silver nanoparticles, are being explored as effective treatment solutions.
- * The performance of these electrodes was characterized through various analytical methods, showing improved surface area and electron transfer rates compared to standard electrodes, which indicates better efficiency.
- * The electrodes were successfully applied for detecting trimethoprim (TMP) in real water and urine samples, achieving low limits of detection and high recovery rates, highlighting their potential in environmental monitoring and health applications.
Article Synopsis
- The study focuses on the generation of nitric oxide (NO) and its significance in cell biology, particularly for blood pressure regulation, while exploring the potential of ruthenium(II) complexes in this area.
- The analysis reveals that the release of NO from ruthenium complexes is influenced by the spin multiplicity of the metal ion, affecting key geometrical parameters such as bond lengths and angles.
- Results indicate that exciting the complex can facilitate NO release, supported by Gibbs free energy data showing lower energy requirements for this process, and electronic spectra aligning with previous experimental findings.
Article Synopsis
- * Various jarosites were prepared and characterized using analytical methods, while dissolution kinetics were analyzed using the Shrinking Core Kinetic Model (SCKM) under varying temperatures and pH levels.
- * Results indicated that temperature significantly affects jarosite stability, with extreme pH values influencing the dissolution, leading to the proposal of a kinetic equation to predict the jarosites' lifespan.
Article Synopsis
- Biomolecules such as cysteine and cytosine are crucial for various physiological functions, but their abnormal levels are linked to diseases like cancer, highlighting the need for effective detection methods.
- A new fluorescent probe, BMTM, was synthesized and characterized, leading to the creation of fluorescent organic inorganic nanohybrids (FONPs) that can selectively detect cysteine and cytosine without interference from other biological compounds.
- Experiments using FONPs showed strong fluorescence for cytosine in yeast cells, while cysteine exhibited negligible fluorescence, and Density Functional Theory (DFT) was utilized to analyze the interactions between the FONPs and these biomolecules.
Article Synopsis
- The study focuses on the synthesis of two oligophenyleneimine pentamers, DAFCHO and FDACHO, which contain terminal aldehydes, using mechanochemistry methods and various diamines.* -
- The compounds were characterized using spectroscopy techniques (¹H and C-NMR, FT-IR, mass spectrometry) and displayed interesting photochromic properties in chloroform when exposed to sunlight, with notable energy band gap values measured.* -
- Electrochemical studies revealed their potential as organic semiconductors, with HOMO and LUMO values indicating favorable electronic properties, and findings were further supported by Density Functional Theory (DFT) calculations.*
Article Synopsis
- A new technique was developed to detect aluminum (Al) in milk and biological samples, which can also identify the antibiotic tetracycline (TC) without interference from other metal ions.
- The method has a low limit of detection (LOD) of 0.00022 mM for Al, with a strong correlation (r = 0.9439) indicated via fluorescence intensity analysis.
- Additionally, carbon dots (CDs) derived from TC can detect Al with an LOD of 0.00050 mM and a slightly lower correlation (r = 0.9404), and this detection was validated in both milk and living yeast cells.
Article Synopsis
- The study investigates the combination of titanium dioxide (TiO) and zinc oxide (ZnO) to create a hybrid material that lowers the band gap energy, enhancing the photo-oxidation of Congo red dye under visible light.
- Analytical techniques like XRD, TEM, AFM, and XPS characterize the nanohybrids, revealing a dominant anatase phase and significant surface plasmon properties from silver nanoparticles (Ag NPs).
- The paper suggests that the interaction between TiO's and ZnO's crystal planes reduces the energy band gap and improves catalyst performance, with potential applications in bio-imaging of yeast cells.
Article Synopsis
- - The study used density functional theory to analyze the structural and electronic properties of 25 phosphonate derivatives, employing the PBEPBE functional with a 6-311++G
- basis set to assess their chemical reactivity through quantum descriptors like HOMO, LUMO, and Hirshfeld charges.
- - A multiple linear regression model was developed to predict the toxicity of phosphonates based on factors such as molecular volume, electronegative atom charge, and HOMO eigenvalue, showing strong internal validation results.
- - The findings suggest that the oxygen atom in the O=P group significantly influences the interaction of phosphonates with the acetylcholinesterase enzyme, contributing to their inhibitory effect and potential toxicity.
Article Synopsis
- The study investigated how effective 2,6-bis[((2-pyridylmethyl)oxy)methyl)]pyridine (BPMMP) is at preventing corrosion of mild carbon steel in hydrochloric acid (HCl), revealing significant reductions in both cathodic and anodic currents during polarization studies.
- Impedance analysis indicated that the effectiveness of BPMMP as a corrosion inhibitor was directly related to its concentration, and recurrence analysis showed changes in Shannon entropy that suggested a higher stability in the presence of the inhibitor.
- The research also utilized density functional theory (DFT) to explore BPMMP's interactions with iron clusters, revealing insights into the structural and electronic behavior of BPMMP before and after forming complexes with iron
Article Synopsis
- The study highlights the environmental impact of jarosite compounds, particularly how they can affect the mobility of toxic elements like lead and arsenic in water and soil.
- It focuses on the dissolution rates of K-Cr(VI)-jarosites, revealing that temperature significantly influences these rates, followed by pH levels, but not the substitution of certain ions within the compound.
- The findings suggest that extreme pH and temperature conditions lead to higher dissolution rates, which is important for understanding the stability and environmental behavior of these compounds.
Article Synopsis
- - The study investigates the relationship between the structural properties of imidazol, benzimidazol, and pyridine derivatives and their effectiveness as corrosion inhibitors using quantum descriptors and a multiple linear regression analysis.
- - Findings reveal that the efficiency of these corrosion inhibitors correlates with factors like aromaticity, electron donor ability, and molecular volume, leading to the development of a quantitative predictive model.
- - Electrochemical impedance spectroscopy (EIS) results validate the model, showing a strong agreement with experimental corrosion inhibition values, and highlight the significance of aromaticity in the adsorption of these compounds on metal surfaces.
Article Synopsis
- A ruthenium complex with a specific ligand was created and its properties were explored through DFT analysis, focusing on oxidation states and reactive sites.
- The complex demonstrates a preference for bonding based on metal oxidation states, with Ru(IV) interacting more readily with hard bases and Ru(II) with soft bases, influenced by the Jahn-Teller effect.
- It effectively oxidizes phenol to benzoquinone using H2O2, with experiments identifying intermediates, while a potential mechanism and rate law for this reaction were also proposed.
Article Synopsis
- Organic nanoparticles (ONPs) made from lipoic acid and its silver (Ag) and gold (Au) doped derivatives were created and analyzed using various techniques like UV-Visible spectroscopy, EDS, and TEM.
- Antibacterial tests showed that ONPs/Ag were particularly effective against bacteria, especially Gram-positive strains like Staphylococcus aureus, outperforming ONPs and ONPs/Au in inhibiting growth.
- Further analysis of the bacteria's cell membranes and bonding characteristics of lipoic acid with Ag or Au was done using scanning electron microscopy (SEM) and computational methods like density functional theory (DFT).
Article Synopsis
- - Imine-linked pyridine-coupled (ILPC) receptors were created and analyzed for their absorption and fluorescence characteristics using both experimental and theoretical methods.
- - These receptors were turned into organic nanoparticles (ONPs) and combined with gold nanoparticles (AuNPs) to selectively identify iodide ions, showing a very low detection limit of 1.4 nM without interference in water.
- - This study marks the first successful use of ONPs-AuNPs for detecting iodide in a nanomolar range in water, demonstrating its application in measuring iodide levels in urine samples.
Article Synopsis
- Two phenyleneimine oligomers, OIC1MS and OIC2MS, were synthesized using both traditional and mechanochemical methods.
- These compounds were characterized using techniques like FT-IR and NMR, and their optical properties were examined with UV-visible spectroscopy, revealing that OIC2MS has notable photochromic characteristics.
- Additionally, their structural and electronic properties were studied using TD-DFT, indicating that mechanosynthesis is a highly effective approach for creating these tetraimines.