Faculty Publications

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2024 - 20254

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Author: search.filters.author.Trivedi, D.R.Subject: search.filters.subject.ultraviolet radiation

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    Colorimetric differentiation of arsenite and arsenate anions using a bithiophene sensor with two binding sites: DFT studies and application in food and water samples
    (Royal Society of Chemistry, 2024) K, K.; Nityananda Shetty, A.N.; Trivedi, D.R.
    Chemosensor N7R1 with two acidic binding sites was synthesized, and the ability of the sensor to differentiate arsenite and arsenate in the organo-aqueous medium was evaluated using colorimetric sensing methods. N7R1 distinguished arsenite with a peacock blue color and arsenate with a pale green color in a DMSO/H2O (9 : 1, v/v) solvent mixture. The specific selectivity for arsenite was achieved in DMSO/H2O (7 : 3, v/v). The sensor demonstrated stability over a pH range of 5 to 12. The computed high binding constant of 9.3176 × 1011 M−2 and a lower detection limit of 11.48 ppb for arsenite exposed the chemosensor's higher potential for arsenite detection. The binding mechanism with a 1 : 2 binding process is confirmed using UV-Vis and 1H NMR titrations, electrochemical studies, mass spectral analysis and DFT calculations. Practical applications were demonstrated by utilizing test strips and molecular logic gates. Chemosensor N7R1 successfully detected arsenite in real water samples, as well as honey and milk samples. © 2024 The Royal Society of Chemistry.
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    Chromogenic Chemosensor for Simultaneous Detection of PO43? and CO32? Anions in Organo-Aqueous Solutions: Application in Arduino Based Electronic Color Sensor Device and Logic Gate
    (John Wiley and Sons Inc, 2024) Dhawale, A.; Trivedi, D.R.
    Three new chromogenic receptors have been synthesized with the primary objective of facilitating the selective recognition of PO43?and CO32? ions in an organo-aqueous medium. R1 and R2 exhibit an extraordinary detection limit aligning with both EPA and WHO guidelines. R1 shows LOD of 0.135 ppm for PO43? and 0.175 ppm for CO32?, while R2 sets forth a LOD of 0.427 ppm for PO43? and 0.729 ppm for CO32?. The binding mechanism involves intramolecular charge transfer (ICT) band are substantiated by comprehensive studies that include UV-Vis titration, 1H-NMR titration, DFT studies and electrochemical studies. Chemosensors were employed in the formulation of logic gate, the fabrication of a paper strip test kit and its application in RGB color sensor device. © 2024 Wiley-VCH GmbH.
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    Rational design of an isatin-based colorimetric and solvatochromic receptor for carbonate ions and its application in molecular-scale logic gates & memory units
    (Elsevier B.V., 2025) Akhil Kumar, M.M.; Dhawale, A.; Trivedi, D.R.
    A simple and highly sensitive isatin-based colorimetric sensor ISAT 3(a-d) was synthesized through a single-step reaction. The as-prepared receptor ISAT 3b with carbonate ions (CO32? ions) shows a significant red shift in the UV–visible absorption spectra and a visible color change from pale yellow to pink. Also, the receptor ISAT 3b shows unique solvatochromic behavior with CO32? ions in different aprotic solvents and solvent compositions. Moreover, the receptor's pink coloration (absorption maxima at 544 nm) with CO32? ions could be reversible by adding HSO4? ions (attain initial pale-yellow color, absorption maxima at 425 nm), which can be repeatable. The observed color changes with spectral shift and reversibility of the receptor with CO32? ions and HSO4? ions provide “ON-OFF” switching for applying molecular logic gates. Receptors exhibited properties, such as reversibility and repeatability, benefit the design of a molecular-scale sequential memory unit with a display of “Writing-Reading-Erasing-Reading”. The real sample analysis was also carried out to prove the practical applicability of receptor (ISAT 3b) for detecting CO32? ions. © 2024 Elsevier B.V.
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    Discriminative ion detection of Hg2+ and Cu2+ and selective recognition of PO43? ions: Real time monitoring in food and water samples and molecular keypad lock integration
    (Elsevier B.V., 2025) Hebbar, S.D.; Trivedi, D.R.
    A series of sensors, designated S3R1-S3R4, were designed and synthesized for the detection of PO43? ions and toxic metals, specifically Hg2+ and Cu2+ ions. The colorimetric detection of PO43? ions using these sensors exhibited a distinct visual color transition from yellow to purple in organo-aqueous media. The intrinsic cavity-like structure in the thiosemicarbazide-based derivative S3R4 significantly enhances the binding affinity for Hg2+ and Cu2+ ions in organic media. Utilizing UV–visible spectroscopic techniques and electrochemical investigations, the binding constants, stoichiometric ratios, limits of detection (LOD), and the electrochemical properties of the sensor-ion complexes were comprehensively characterized alongside their stability. Density Functional Theory (DFT) validation studies elucidated the binding mechanisms involved in the ion detection process. The LOD for PO43? with S3R1 was determined to be 0.28 ppm, while the LODs for Hg2+ and Cu2+ with S3R4 were found to be 0.15 ppm and 0.15 ppm, respectively. The significant binding constants and detection limits underscore the potential of S3R1-S3R4 as real-time sensors for detecting PO43?, Cu2+, and Hg2+ ions in environmental applications. Furthermore, the integration of molecular keypad locks and logic gate constructions highlights the applicability of these sensors in molecular communication systems. © 2025 Elsevier B.V.