28 results on '"Vairaperumal Tharmaraj"'
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2. List of contributors
- Author
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Abro, Naveed Qasim, primary, Achiou, Brahim, additional, Adhikari, Priyanka, additional, Alami Younssi, Saad, additional, Ali, Banafsheh Haji, additional, Ali, Zafar, additional, Baghdadi, Majid, additional, Bajpayee, Anand Kumar, additional, Balouch, Aamna, additional, Baran, Chhavi, additional, Bayuseno, A.P., additional, Bhardwaj, Abhishek Kumar, additional, Bhardwaj, Laxmi Kant, additional, Bharti, Abhi Sarika, additional, Bhuyan, Rajashree, additional, Bordoloi, Palakshi, additional, Breida, Majda, additional, Bui, Minh Quy, additional, Chafiq Elidrissi, Zakariya, additional, Chandola, Dinesh, additional, Chang, Zhen Hong, additional, Chauhan, Shikha Baghel, additional, Choudhury, Kristi Priya, additional, Darbha, Gopala Krishna, additional, Das, Parna, additional, Das, Ranjita S., additional, Debnath, Shrestha, additional, Devika, Y., additional, Dhyani, Vibhash, additional, Dikshit, Anupam, additional, El Machtani Idrissi, Doha, additional, Essate, Ahlam, additional, Gaur, Manish, additional, Geed, Sachin Rameshrao, additional, Ghosal, Partha Sarathi, additional, Ghosh, Dipankar, additional, Gunarto, Chintya, additional, Gupta, Ena, additional, Ismail, R., additional, Jagirani, Muhammad Saqaf, additional, Jamari, J., additional, Jha, Saket, additional, Jindal, Tanu, additional, Kakakhel, Mian Adnan, additional, Kalhoro, Muhammad Siddique, additional, Kataria, Navish, additional, Katyal, Deeksha, additional, Khandelwal, Nitin, additional, Khuhawar, Aftab Hussain, additional, Kori, Abdul Hameed, additional, Kouzi, Youness, additional, Kumar, Anupama, additional, Kumar, Naresh, additional, Laghari, Sakib Hussain, additional, Lyly, Leow Hui Ting, additional, Mahesar, Sarfaraz Ahmed, additional, Majumder, Abhradeep, additional, Malik, Aastha, additional, Mandal, Pubali, additional, Memon, Najma, additional, Misra, Charu, additional, Muryanto, S., additional, Narwal, Nishita, additional, Neogi, Newton, additional, Noor, Uroosa, additional, Ojha, Rudra Prakash, additional, Ouammou, Mohamed, additional, Pandey, Rahul, additional, Pathak, Ashok Kumar, additional, Purwar, Shalini, additional, Puspitasari, Nathania, additional, Rakib, Md. Refan Jahan, additional, Retnoningtyas, Ery Susiany, additional, Samal, Kulbhushan, additional, Sarkar, Soumita, additional, Saxena, Shikha, additional, Selvaraj, Devi, additional, Sherazi, Syed Tufail Hussain, additional, Shukla, Mohee, additional, Shukla, Rohit, additional, Singh, Abhimanyu Kumar, additional, Singh, Ravikant, additional, Soetaredjo, Felycia Edi, additional, Soni, Shashi, additional, Subhan, Md Abdus, additional, Teow, Yeit Haan, additional, Thathola, Pooja, additional, Tiwari, Ajay Kumar, additional, Tokas, Rajat, additional, Toppo, Swati Rose, additional, Tripathi, Shipra, additional, Truong, Thi Thao, additional, Uttam, Kailash Narayan, additional, Vairaperumal, Tharmaraj, additional, Verma, Jitendra Singh, additional, Verma, Manisha G., additional, and Yadav, Manoj Kumar, additional
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- 2024
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3. Application and characterization of nonbiogenic synthesized nanomaterials
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Selvaraj, Devi, primary and Vairaperumal, Tharmaraj, additional
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- 2024
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4. Microplastics in packaged water, community stored water, groundwater, and surface water in rivers of Tamil Nadu after the COVID-19 pandemic outbreak
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Pavithra, K., Vairaperumal, Tharmaraj, KS, Vignesh, Mukhopadhyay, Moitraiyee, Malar, P., and Chakraborty, Paromita
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- 2024
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5. Chapter 10 - Microplastic in the environment: sources, workflow, identification techniques, and impacts on human health
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Vairaperumal, Tharmaraj, Selvaraj, Devi, and Chakraborty, Paromita
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- 2024
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6. Resorcinarene Crowns as Versatile Host Molecules and Their Potential Applications
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Selvaraj Devi, Somasundaram Anbu Anjugam Vandarkuzhali, and Vairaperumal Tharmaraj
- Abstract
Resorcinarene crowns are significant building blocks for supramolecularchemistry. Resorcinarenes are part of the calixarenes family and are macrocyclic,bowl-shaped molecules. Derived from four resorcinol subunits, they have hydroxygroups at the wide rim of the bowl. These cavities were utilized for their potentialrecognition of racemic guests and catalysis applications. In this chapter, we focused onthe overview of synthesis, conformational properties of resorcinarenes crown and theirpotential applications such as separation technique using high performance liquidchromatography (HPLC), gas chromatography (GC) and ion chromatrography (IC). Inaddition, they are also used as chemo sensors, antibacterial and antioxidant agents,contrast agents, nanoparticles synthesis and catalytic systems. Finally, we concludedthe chapter with the significance of resorcinarenes crown.
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- 2022
7. Role of Surface Oxidation Layer in Electroless Deposition of Silver Nanoparticles on Silicon Crystal for Surface-Enhanced Raman Scattering Measurements
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Vairaperumal Tharmaraj and Jyisy Yang
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- 2022
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8. List of contributors
- Author
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Ahmad, Md Altamash, Allam, Bharat Kumar, Anand, Aryan, Arasu, Ponnusamy Thillai, Arora, Vimal, Arunima, Ashana, Segni Asafa, Bajaj, Himani, Banerjee, Sushmita, Behera, Bhaskar, Behera, Bijay Kumar, Behera, Jiban Kumar, Bhattacharya, Manojit, Biswas, Gargi, Chakraborty, Paromita, Chandrasekaran, Balakumar, Chopra, Bhawna, Dash, Ratnakar, Dash, Subhakanta, Dei, Jyotsna, Deswal, Geeta, Devi, Mohini, Devi, Priyanka, Dey, Shipa Rani, Dey, Sujata, Dhingra, Ashwani K., Drouiche, Nadjib, Ganguly, Dibyangana, Gangwar, Chinky, Garg, Vinod K., Gautam, Rupesh Kumar, Gazi-Khan, Lameesa, Ghosh, Arpita, Ghosh, Dipankar, Goel, Divya, Gonzalez-Torres, Alyson D., Goyal, Rajat, Grewal, Ajmer Singh, Gulzar, Aadil, Gupta, Manjul, Gupta, Piyush, Gupta, Sumeet, Haque, Shama E., Ilango, Vijaya, Izah, Sylvester C., Joshi, Sarita, Kabra, Atul, Kamili, Azra N., Kar, Biswabandita, Kaur, Amardeep, Kaur, Gagandeep, Kaur, Rajwinder, Kaushal, Jyotsna, Kaushik, Peeyush, Kriplani, Priyanka, Kumar, Deepak, Kumar, Indresh, Kumar, Jitendra, Kumar, Maneesh, Kumar, Manoj, Kumar, Nitin, Kumar, Prasann, Kumar, Pratik, Kumar, Rahul, Kumari, Arti, Kumari, Neeta, Kushwaha, Manzari, Lang, Damanpreet Kaur, Maharana, Jitendra, Majeed, Lone Rafiya, Malikia, Cherubala N., Manohar, Arumugam, Markandeya, McCarthy, Mark J., Mishra, Anuradha, Mishra, Brijesh Kumar, Mishra, Nishish, Mishra, Pabitra, Mohan, Devendra, Mohanty, Itishree, Murugan, Arumugam, Naik, Radhey Mohan, Nautiyal, Ujjval, Nayak, Rashmi, Nayak, Rudra Prasanna, Nguyen, Thuong Tuan, Nisar, Bisma, Nõges, Peter, Nõges, Tiina, Ogwu, Matthew C., Pahalvi, Heena Nisar, Panda, Laxmidhar, Pandey, Amit Ranjan, Pandey, Pradeep Kumar, Pandey, Rishi Ranjan, Pandey, Soumya, Parida, Satya Narayan, Patra, Bidyutlata, Pradhan, Jyotirmayee, Pradhan, Smruti Priyambada, Pradhan, Sukanta Kumar, Ram, Siya, Rani, Lata, Rashid, Habiba, Rashid, Sumaira, Ravikumar, C.R., Rout, Ajaya Kumar, Sahu, Alka, Saini, Balraj, Sarkar, Joy, Selvaraj, Devi, Sen, Mitun, Senthilkumar, S., Shankar, Shiv, Sharma, Anjali, Sharma, Devkant, Sharma, Khushbu, Sharma, Prateek, Sharma, Ram Babu, Shukla, Dericks Praise, Shukla, Sheo Prasad, Siddha, Swayam, Singh, Aakansha, Singh, Indu, Singh, Nakshatra Bahadur, Singh, Neeraj Kumar, Singh, Varinder, Sinha, Nilothpal, Siva, V., Siyaram, Soni, Richa, Sood, Parul, Srivastav, Arun Lal, Stansfield, Aidan, Tripathi, Avnish Kumar, Truong, Thi Thao, Usman, Usman Lawal, Vairaperumal, Tharmaraj, Vuong, Truong Xuan, Yadav, Manish, Yadav, Mayank, and Yaseen, Bushra
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- 2024
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9. Bio-Mediated Synthesis of Quantum Dots for Fluorescent Biosensing and Bio-Imaging Applications
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Vairaperumal Tharmaraj and S. Devi
- Subjects
Bio imaging ,Materials science ,Quantum dot ,Nanotechnology ,Biosensor ,Fluorescence - Abstract
Quantum dots (QDs) have received great attention for development of novel fluorescent nanoprobe with tunable colors towards the near-infrared (NIR) region because of their unique optical and electronic properties such as luminescence characteristics, wide range, continuous absorption spectra and narrow emission spectra with high light stability. Quantum dots are promising materials for biosensing and single molecular bio-imaging application due to their excellent photophysical properties such as strong brightness and resistance to photobleaching. However, the use of quantum dots in biomedical applications is limited due to their toxicity. Recently, the development of novel and safe alternative method, the biomediated greener approach is one of the best aspects for synthesis of quantum dots. In this Chapter, biomediated synthesis of quantum dots by living organisms and biomimetic systems were highlighted. Quantum dots based fluorescent probes utilizing resonance energy transfer (RET), especially Förster resonance energy transfer (FRET), bioluminescence resonance energy transfer (BRET) and chemiluminescence resonance energy transfer (CRET) to probe biological phenomena were discussed. In addition, quantum dot nanocomposites are promising ultrasensitive bioimaging probe for in vivo multicolor, multimodal, multiplex and NIR deep tissue imaging. Finally, this chapter provides a conclusion with future perspectives of this field.
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- 2021
10. Biosensor Devices Based on Metal Oxide Materials
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S. Devi and Vairaperumal Tharmaraj
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chemistry.chemical_classification ,chemistry.chemical_compound ,Materials science ,Transducer ,chemistry ,Biomolecule ,technology, industry, and agriculture ,Oxide ,Nanotechnology ,macromolecular substances ,Biocompatible material ,Biosensor ,Signal - Abstract
Biosensor is a device that detects biological signals by converting biological signals into detectable electronic signals. Biosensor involves the combination of bioreceptors like proteins/enzymes, DNA, and RNA that interact with some specific bioanalytes like antibody–antigen and a transducer that converts the interaction into a useful analytical signal. Several types of biosensor devices have been successfully developed and utilized in the field of biomedical, food industries, and environment. The conventional biosensor devices have some limitations such as poor selectivity, low sensitivity, and expensive fabrication. Therefore, the development of a wide range of detection purposes, nontoxic, highly stable and biocompatible with low cost biosensing devices, is still crucial and challenging.
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- 2021
11. Photoelectrochemical Process for Hydrogen Production
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S. Devi and Vairaperumal Tharmaraj
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Materials science ,Chemical engineering ,Photoelectrochemical process ,Hydrogen production - Published
- 2020
12. Quantum Dots in Green Photocatalytic Applications for Degradation of Environmental Pollutants and Hydrogen Evolution
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Vairaperumal Tharmaraj and S. Devi
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Pollutant ,Sustainable development ,Potential well ,Quantum dot ,law ,Solar cell ,Photocatalysis ,Environmental science ,Environmental impact of the energy industry ,Nanotechnology ,Energy storage ,law.invention - Abstract
In recent years, environmental pollutions and energy issues have attracted much attention for the sustainable development of human life. It is of great challenge for the researcher to find a clean, biocompatible, nontoxic, and environment-friendly method for solving the problems associated with the environment. Photocatalysis is one of the effective strategies for mitigating the energy crisis and environmental pollutions. Several photocatalysts were developed for the efficient degradation of environmental pollutants into useful products. Mainly, quantum dot (QD)-based photocatalysts have attracted the researchers due to their attractive properties such as quantum confinement effect, large surface area, and high catalytic activity that makes its promising applications in the field of photocatalysis, sensing, light-emitting diodes, energy storage devices, bioimaging, and solar cell.
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- 2019
13. Nanomaterials for Advanced Analytical Applications in Chemo- and Biosensors
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S. Devi and Vairaperumal Tharmaraj
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chemistry.chemical_classification ,Materials science ,chemistry ,Biocompatibility ,Nanosensor ,Biological species ,Biomolecule ,Nanotechnology ,Highly selective ,Sensing system ,Biosensor ,Nanomaterials - Abstract
Nanomaterials with unique optical properties and biocompatibility have been widely employed for designing and fabricating highly selective and sensitive nanosensors for the detection of various chemical and biological species. The development of nanomaterial-based chemo- and biosensors is studied usually under direct spectroscopic and reagent-mediated sensor platforms using both unmodified and surface-functionalized nanomaterials. This chapter mainly focuses on selective sensing of chemical and biological molecules using various types of nanomaterials. The main readouts are absorption (colorimetric, UV-visible), fluorescence, Raman/SERS spectroscopic, and electrochemical sensing techniques. The detailed discussion on the design of nanomaterial-based sensing systems, sensing principle, sensing method, and their signaling mechanisms has been provided. The sensing systems can also be ideally utilized for real-time applications.
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- 2019
14. An oxidation layer for regulating galvanically grown silver nanoparticles on silicon crystal for highly sensitive surface-enhanced Raman scattering measurements
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Vairaperumal Tharmaraj and Jianhua Yang
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Materials science ,Inorganic chemistry ,Substrate (chemistry) ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Silver nanoparticle ,0104 chemical sciences ,Monocrystalline silicon ,chemistry.chemical_compound ,symbols.namesake ,Adsorption ,Hydrofluoric acid ,chemistry ,symbols ,Galvanic cell ,General Materials Science ,0210 nano-technology ,Layer (electronics) ,Raman scattering - Abstract
In this study, a new method was developed in which an oxidation layer is used to regulate the morphology of silver nanoparticles (AgNPs) formed on Si crystals during galvanic displacement (GD). Using an oxidation layer yielded reproducible and stable AgNPs@Si substrates for sensitive surface-enhanced Raman scattering (SERS) measurements. The estimated SERS enhancement was at least an order of magnitude greater than for substrates prepared using a conventional GD method. The formation of Si–O− on the Si surface increased the adsorption of the AgNPs. Highly reproducible results were obtained, with a relative standard deviation of approximately 5%. To investigate the role of the oxidation layer and to optimize the reaction conditions, the oxidation layer thickness and chemical composition of the reaction solution were adjusted. The degree of aggregation in AgNP formation was mainly controlled by the thickness of the oxidation layer, whereas the size of the AgNPs was affected by both the concentration of AgNO3 and hydrofluoric acid in the reaction solution and the GD reaction time. When the optimized reaction conditions were used, the AgNPs@Si substrate had an enhancement factor of >107.
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- 2016
15. Surfactant-assisted electroless deposition of silver nanoparticles on Ge crystal for ultra-sensitive detection by surface-enhanced infrared absorption spectroscopy
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Gadupudi Purna Chandra Rao, Jianhua Yang, and Vairaperumal Tharmaraj
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Ammonium bromide ,Chemistry ,General Chemical Engineering ,Inorganic chemistry ,Cationic polymerization ,Infrared spectroscopy ,Substrate (chemistry) ,General Chemistry ,Silver nanoparticle ,Reaction rate ,Crystal ,chemistry.chemical_compound ,Pulmonary surfactant ,Chemical engineering - Abstract
Silver nanoparticles (AgNPs) were electrolessly grown on Ge crystal to form substrate for ultra-sensitive detection by surface-enhanced infrared absorption (SEIRA) measurements. To effectively control the morphology of AgNPs, a surfactant-assisted electroless deposition method was proposed in this work. By addition of surfactant into the reaction solution, both reaction rate and behavior in agglomeration of AgNPs were significantly altered. To explore the role of surfactants, three types of surfactants were studied; cationic, anionic and Zwitterionic surfactants. Among them, cationic surfactant of cetyl trimethyl ammonium bromide (CTAB) showed best SEIRA effect as a labile interaction exists between the amine group in CTAB and the formed AgNPs. Also, the hydrophobic long tail of CTAB effectively protects the AgNPs from serious agglomeration. For Zwitterionic surfactants of amino acids, the polar groups on both ends caused severe percolation of AgNPs. With a strong interaction to AgNPs, anionic surfactant of sodium dodecyl benzene sulfonate (SDBS) regulated the AgNPs into a square shaped crystal, which resulted a distortion of infrared absorption band. Based on the obtained results, the substrates prepared with the optimal condition found in this work were at least 5 times higher than that of conventional electroless deposition method. The overall increase of the infrared absorption falls in a range between 300 to 400 times.
- Published
- 2015
16. Sensitive and selective colorimetric detection of Cu2+in aqueous medium via aggregation of thiomalic acid functionalized Ag nanoparticles
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Vairaperumal Tharmaraj and Jianhua Yang
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Detection limit ,Thiomalates ,Silver ,Metal ions in aqueous solution ,Analytical chemistry ,Metal Nanoparticles ,Water ,Sensitivity and Specificity ,Biochemistry ,Silver nanoparticle ,Analytical Chemistry ,Wavelength ,chemistry.chemical_compound ,chemistry ,Electrochemistry ,Environmental Chemistry ,Colorimetry ,Carboxylate ,Surface plasmon resonance ,Thiomalic acid ,Quantitative analysis (chemistry) ,Spectroscopy - Abstract
A simple and effective colorimetric method for determination of Cu(2+) in real samples was developed. In this method, thiomalic acid functionalized silver nanoparticles (TMA-AgNPs) were prepared and changes in solution color, induced by the aggregation of TMA-AgNPs in the presence of Cu(2+), were employed for quantitative analysis. The surface plasmon resonance (SPR) band of our synthesized TMA-AgNPs was located at 392 nm and shifted to a longer wavelength after aggregation due to the interactions between carboxylate and Cu(2+). A band intensity ratio of A455/(A392-A455) was constructed and used to correlate with the concentration of Cu(2+). A linear relationship was found with a linear response up to 50 nM of Cu(2+). Due to the formation of a stable carboxylate Cu(2+) complex, highly sensitive detection of Cu(2+) was achieved with the estimated detection limit approaching 1 nM. Moreover, the formation of the stable complex leads to high selectivity in the detection of Cu(2+), which was verified by examination of 12 other metal ions. In the detection of Cu(2+) in real samples, results indicated that our proposed method is simple, sensitive and selective for application in such measurements.
- Published
- 2014
17. A Ratiometric Tetrazolylpyridine-Based 'Turn-On' Fluorescent Chemosensor for Zinc(II) Ion in Aqueous Media
- Author
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Palanichamy Kaleeswaran, Kasi Pitchumani, Ismail Abulkalam Azath, and Vairaperumal Tharmaraj
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inorganic chemicals ,Detection limit ,Proton ,Metal ions in aqueous solution ,Inorganic chemistry ,chemistry.chemical_element ,General Chemistry ,Zinc ,Photochemistry ,Fluorescence ,Ion ,chemistry.chemical_compound ,chemistry ,Intramolecular force ,Pyridine - Abstract
The highly selective ratiometric “turn-on” fluorescent sensing of Zn2+ ion involving 2-(1H-tetrazole-5-yl)pyridine (2PT) in aqueous medium is reported, which is not observed when other metal ions are present. Upon 2PT binding selectively with Zn2+ ion, a fluorescence enhancement is observed that is attributed to an enhancement of localized emission and suppression of excited-state intramolecular proton transfer. The described sensing system involving 2PT is also successfully applied to the detection of Zn2+ ion in real samples with a detection limit of 7.5×10−7 M.
- Published
- 2014
18. An acyclic, dansyl based colorimetric and fluorescent chemosensor for Hg(II) via twisted intramolecular charge transfer (TICT)
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Kasi Pitchumani and Vairaperumal Tharmaraj
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Models, Molecular ,Cations, Divalent ,Chemistry ,Drinking Water ,Metal ions in aqueous solution ,High selectivity ,Analytical chemistry ,Charge (physics) ,Mercury ,Time-dependent density functional theory ,Photochemistry ,Sensitivity and Specificity ,Biochemistry ,Fluorescence ,Analytical Chemistry ,Ion ,Spectrometry, Fluorescence ,Rivers ,Intramolecular force ,Environmental Chemistry ,SN2 reaction ,Spectroscopy ,Fluorescent Dyes - Abstract
An efficient fluorescent chemosensor for Hg(2+) ion, based on 5-(dimethylamino)-N-(2-mercaptophenyl)naphthalene-1-sulfonamide, has been developed. It exhibits Hg(2+)-selective on-off fluorescence quenching behavior via twisted intramolecular charge transfer (TICT) mechanism, which is rationalized by time dependent density functional theory (TD-DFT) calculations. The system exhibits visible color change from colorless to gray upon Hg(2+) binding with very high selectivity and sensitivity (as low as 5.0×10(-10)molL(-1)) over other metal ions such as K(+), Na(+), Ag(+), Mn(2+), Ca(2+), Ba(2+), Fe(2+), Zn(2+), Pb(2+), Cu(2+), Sn(2+), Cd(2+), Ni(2+) and Co(2+). The present sensing system is also successfully applied for the detection of Hg(2+) ion in real samples.
- Published
- 2012
19. Autofluorescence in BrdU-Positive Cells and Augmentation of Regeneration Kinetics by Riboflavin
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Kuppusamy Amutha, Selvan Christyraj Jackson Durairaj, Sivassubramaniam Sudhakar, Subramanian Elaiya Raja, Kasi Pitchumani, Ambrose Edith Arul Jane, Vairaperumal Tharmaraj, Ramamoorthy M. Kalidas, Selvan Christyraj Johnson Retnaraj Samuel, Sudalai Mani Dinesh, and Yesudhason Beryl Vedha
- Subjects
Cytoplasm ,Riboflavin ,Cell ,Biology ,Fluorescence ,chemistry.chemical_compound ,Species Specificity ,Cell Movement ,medicine ,Animals ,Regeneration ,Oligochaeta ,Cell Nucleus ,Epidermis (botany) ,Muscles ,Regeneration (biology) ,Cell Biology ,Hematology ,Immunohistochemistry ,Cell biology ,Autofluorescence ,medicine.anatomical_structure ,Bromodeoxyuridine ,Epidermal Cells ,Biochemistry ,chemistry ,Chromatography, Thin Layer ,Epidermis ,Blastema ,Developmental Biology - Abstract
The earthworm, Eudrilus eugeniae, has a prodigious ability to regenerate lost segments. The skin of the worm has an outermost epidermal layer followed by a thick circular muscle layer and an innermost thin longitudinal cell layer. During the process of regeneration, the circular muscle layer decreased in thickness, and longitudinal cell layer increased. The histological analysis of the regenerated worm shows that the longitudinal cell layer forms the regeneration blastema. BrdU-labeling retention assay confirmed that the circular muscle and longitudinal cell layers have BrdU-positive cells, which migrate from the adjacent segments to the regeneration blastema. In addition, it was noted that the cells of the earthworm, E. eugeniae, have the property of autofluorescence. Autofluorescence was found in the cytoplasm, but not in the nucleus. It has been also found that the major source for autofluorescence is riboflavin. Further, it was also demonstrated that supplementation with riboflavin increases the rate of regeneration, while regeneration was hampered by reduced levels of riboflavin. The importance of riboflavin in regeneration was also confirmed by rescue assay. In addition, it was also identified that BrdU-positive cells are highly fluorescent compared to the surrounding cells.
- Published
- 2012
20. Clay encapsulated ZnO nanoparticles as efficient catalysts for N-benzylation of amines
- Author
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Amarajothi Dhakshinamoorthy, Pitchai Visuvamithiran, Kasi Pitchumani, and Vairaperumal Tharmaraj
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Materials science ,Process Chemistry and Technology ,Inorganic chemistry ,Nanoparticle ,chemistry.chemical_element ,General Chemistry ,Powder xrd ,Zinc ,Heterogeneous catalysis ,Catalysis ,Chemical engineering ,chemistry ,Zno nanoparticles ,High-resolution transmission electron microscopy ,Reusability - Abstract
ZnO nanoparticles encapsulated in K10-clay (K10–ZnO) are synthesised and characterised by UV-DRS, Emission spectra, powder XRD, SEM and HRTEM analyses. The constrained space and also the polar active sites in the clay support stabilise zinc oxide nanoparticles by preventing that aggregation and consequently no extra-capping agent is required. The synthesised ZnO nanoparticles are used for the efficient N-benzylation of anilines and the reusability of the catalyst is also studied. A suitable mechanism is proposed for this transformation.
- Published
- 2011
21. Synthesis and characterization of fluorophore attached silver nanoparticles
- Author
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Kasi Pitchumani, T. Anitha Sironmani, Vairaperumal Tharmaraj, and S.C.G. Kiruba Daniel
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chemistry.chemical_compound ,Materials science ,Fluorophore ,chemistry ,Mechanics of Materials ,In vivo ,Permeability (electromagnetism) ,Starch ,Drug delivery ,Biophysics ,Organic chemistry ,General Materials Science ,Silver nanoparticle - Abstract
Silver nanoparticles stabilized by soluble starch were synthesized and characterized. In vivo studies in rats showed no toxicity and revealed their distribution in various tissues and permeability across BBB. This starch stabilized silver nanoparticles have good biological characteristics to act as a potential promising vector for gene/drug delivery.
- Published
- 2011
22. Toxicity and immunological activity of silver nanoparticles
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T. Anitha Sironmani, Kasi Pitchumani, S.C.G. Kiruba Daniel, and Vairaperumal Tharmaraj
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Geology ,Nanotechnology ,Gene delivery ,Neurotransmission ,Silver nanoparticle ,chemistry.chemical_compound ,Montmorillonite ,Immune system ,Biochemistry ,chemistry ,Geochemistry and Petrology ,Toxicity ,Distribution (pharmacology) ,Potential toxicity - Abstract
In the present study silver nanoparticles were synthesized and the biological distribution as well as the potential toxicity was studied. Two different concentrations of silver nanoparticles entrapped in montmorillonite were tested in Swiss mice. The animal study demonstrated that the Ag (0) -montmorillonite was nontoxic, showed no immune response, exhibited increased blood half-life, crossed BBB and increased neurotransmission. These observations indicated that Ag (0) -montmorillonite enables diverse applications in life sciences such as drug development, protein detection and gene delivery for any organs in broad, lungs and brain in particular.
- Published
- 2010
23. Alginate stabilized silver nanocube-Rh6G composite as a highly selective mercury sensor in aqueous solution
- Author
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Vairaperumal Tharmaraj and Kasi Pitchumani
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Aqueous solution ,Materials science ,Silver ,Alginates ,Metal ions in aqueous solution ,Hexuronic Acids ,Inorganic chemistry ,Composite number ,Water ,Mercury ,Fluorescence ,Ion ,Nanostructures ,Excipients ,Solutions ,Spectrometry, Fluorescence ,Glucuronic Acid ,SN2 reaction ,General Materials Science ,Qualitative inorganic analysis ,Particle Size ,High-resolution transmission electron microscopy ,Water Pollutants, Chemical - Abstract
Alginate-stabilized silver nanocubes are synthesized via a reduction method and are characterized by UV-Vis and fluorescence spectroscopies, SEM, AFM and HRTEM analyses. A silver nanocubes (Ag NCbs) based sensor for detecting Hg2+ ions in aqueous solution has been developed using Rh6G as an external spectroscopic probe. Using this system, Hg2+ ions (as low as 1×10(-10) mol L(-1)) are recognized in aqueous media via a colorimetric method with very high selectivity and sensitivity over other metal ions namely Fe2+, Zn2+, Pb2+, Cu2+, Sn2+, Cd2+, Ni2+, and Co2+.
- Published
- 2011
24. d-Glucose sensing by (E)-(4-((pyren-1-ylmethylene)amino)phenyl) boronic acid via a photoinduced electron transfer (PET) mechanism
- Author
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Kasi Pitchumani and Vairaperumal Tharmaraj
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chemistry.chemical_compound ,chemistry ,D-Glucose ,General Chemical Engineering ,General Chemistry ,Time-dependent density functional theory ,Photochemistry ,Sensing system ,Acceptor ,Fluorescence ,Photoinduced electron transfer ,Boronic acid - Abstract
An efficient D-glucose selective pyreneimine monoboronic acid probe, based on a photoinduced electron transfer (PET) mechanism, has been developed. The analyses of the spectral changes in the UV-Vis. and fluorescence studies suggest that probe 1 shows an excellent response to D-glucose with a high association constant in a DMSO medium. Photoinduced electron transfer (PET) from the pyreneimine donor to the boronic acid acceptor present is proposed to be responsible for the observed sensing response, which is rationalized by time dependent density functional theory (TD-DFT) calculations. The present sensing system is also successfully applied to the detection of D-glucose in glucose injections.
- Published
- 2013
25. A highly selective ratiometric fluorescent chemosensor for Cu(ii) based on dansyl-functionalized thiol stabilized silver nanoparticles
- Author
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Vairaperumal Tharmaraj and Kasi Pitchumani
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chemistry.chemical_classification ,Detection limit ,Aqueous solution ,Metal ions in aqueous solution ,Biomedical Engineering ,General Chemistry ,General Medicine ,Photochemistry ,Fluorescence ,Silver nanoparticle ,chemistry.chemical_compound ,chemistry ,Thiol ,General Materials Science ,Selectivity ,Acetonitrile - Abstract
A fluorescent chemosensor for Cu2+ ions based on dansyl-functionalized thiol stabilized silver nanoparticles containing 2-aminothiophenyl units as the Cu2+ binding sites is developed. A decrease in fluorescence at 497 nm and an increase in fluorescence at 410 nm with an isoemissive point at 445 nm upon the addition of Cu2+ ions is attributed to the formation of a Cu2+ complex in aqueous acetonitrile based on an energy transfer mechanism. This sensor has excellent sensitivity and selectivity over other metal ions and has a detection limit as low as 5.0 × 10−10 mol L−1.
- Published
- 2013
26. An intramolecular charge transfer (ICT) based chemosensor for silver ion using 4-methoxy-N-((thiophen-2-yl)methyl)benzenamine
- Author
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S. Devi, Kasi Pitchumani, and Vairaperumal Tharmaraj
- Subjects
Ions ,Detection limit ,Silver ,Chemistry ,Methanol ,Metal ions in aqueous solution ,Water ,Charge (physics) ,Thiophenes ,Mass spectrometry ,Photochemistry ,Biochemistry ,Medicinal chemistry ,Fluorescence ,Analytical Chemistry ,Ion ,Spectrometry, Fluorescence ,Metals ,Intramolecular force ,Electrochemistry ,Quantum Theory ,Environmental Chemistry ,Qualitative inorganic analysis ,Spectroscopy ,Fluorescent Dyes - Abstract
4-Methoxy-N-((thiophen-2-yl)methyl)benzenamine was found to be a highly selective chemosensor for Ag(+) ion in methanol-water (1 : 1 v/v) mixture over other metal ions such as Na(+), K(+), Li(+), Cu(+), Ba(2+), Cd(2+), Co(2+), Cu(2+), Fe(2+), Hg(2+), Mn(2+), Ni(2+), Pb(2+) and Zn(2+) with a limit of detection (LOD) is 5.0 × 10(-6) mol L(-1). Upon binding to Ag(+) ion, a strong fluorescent enhancement is observed which is attributed to an increase in intramolecular charge transfer (ICT). The proposed mechanism is strongly supported by TD-DFT calculations.
- Published
- 2012
27. Emerging Predictors by Non-HDL-C/HDL-C Ratio and Novel Biomarkers for Coronary Slow Flow Phenomenon.
- Author
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Vairaperumal T, Tsai ZY, and Liu PY
- Abstract
The coronary slow-flow (CSF) phenomenon is a condition characterized by delayed coronary opacification during diagnostic angiography without the presence of epicardial coronary artery disease. This mini-review explores various emerging predictors and biomarkers associated with CSF, aiming to address the potential diagnostic tools. A comprehensive analysis of recent studies has investigated different biomarkers, including growth differentiation factor 15, galectin 3, microRNA (miRNA)-22, miRNA-155, interleukin 34, soluble vascular cell adhesion molecule-1, long non-coding RNA, plasma choline, adropin, and lipid markers non-high-density lipoprotein cholesterol (HDL-C)/HDL-C ratio to enhance understanding and predict CSF. Additionally, we have summarizes the major findings and significant limitations observed in various studies on CSF biomarkers. The implications of these findings suggest significant advancements in personalized treatment strategies and improved prognostic outcomes for patients exhibiting CSF., Competing Interests: All the authors declare no conflict of interest.
- Published
- 2024
- Full Text
- View/download PDF
28. Optical Nanobiosensor-Based Point-of-Care Testing for Cardiovascular Disease Biomarkers.
- Author
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Vairaperumal T, Huang CC, and Liu PY
- Subjects
- Humans, Biomarkers, Point-of-Care Testing, Cardiovascular Diseases diagnosis, Nanostructures, Biosensing Techniques
- Abstract
Cardiovascular disease is a global health threat, and detecting cardiac biomarkers is essential for early-stage diagnosis and personalized treatment. Traditional approaches have limitations, but optical nanobiosensors offer rapid, highly selective, and sensitive detection. Optical nanobiosensors generate biosignals that transfer light signals while analytes bind with the bioreceptors. Optical nanobiosensors have advantages such as ease of monitoring, low cost, a wide detection range, and high sensitivity without any interference. An optical nanobiosensor platform is a promising approach for point-of-care cardiac biomarker detection with a low detection limit. This review mainly focuses on the detection of cardiovascular disease biomarkers based on various optical nanobiosensor approaches that have been reported during the last five years, and we have categorized them based on optical signal readouts. A detailed discussion of the classification of cardiovascular disease biomarkers, design strategies of optical biosensors, types of optically active nanomaterials, types of bioreceptors, functionalization techniques, various assay types, and sensing mechanisms is presented. Then, we summarize the optical signaling readout-based various nanobiosensors systems for the detection of cardiovascular disease biomarkers. Finally, we summarize and conclude with the recent development of point-of-care testing (PoCT) for cardiovascular disease biomarkers used in various optical readout techniques.
- Published
- 2023
- Full Text
- View/download PDF
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