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Vijayan A, Prakash J. Unveiling angular sweep total fluorescence Spectroscopy:A novel multidimensional technique for analysis of complex multi-fluorophoric systems. Talanta 2024; 271:125662. [PMID: 38241926 DOI: 10.1016/j.talanta.2024.125662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 01/21/2024]
Abstract
Analyzing multi-fluorophoric real systems without pre-processing is challenging, often addressed with unconventional fluorescence techniques and chemometrics. In this context, we introduce a novel addition - 'Angular Sweep Total Fluorescence Spectroscopy (ASTFS),' to the arsenal of multidimensional steady-state fluorescence spectroscopic techniques. ASTFS utilizes a series of variable angle synchronous fluorescence spectra, strategically covering the fluorescence region between the first and second-order Rayleigh scattering ridges. The plot features a minimal data matrix size, avoids Rayleigh scattering signals, and incurs no blind regions. The study delves into the instrumental configurations for spectral acquisition, highlights the enhanced spectral resolution due to the band-narrowing effect, and discusses other notable features of the ASTFS plot. Further, this technique is reported to be effective in analyzing analytes in complex systems with strong background fluorescence, such as milk. The antibiotic- Norfloxacin is quantified via minimal pre-processing in milk samples and yields excellent analytical figures of merit.
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Affiliation(s)
- Anupama Vijayan
- Department of Chemistry, School of Basic and Applied Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India
| | - John Prakash
- Department of Chemistry, School of Basic and Applied Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India.
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Olla C, Cappai A, Porcu S, Stagi L, Fantauzzi M, Casula MF, Mocci F, Corpino R, Chiriu D, Ricci PC, Carbonaro CM. Exploring the Impact of Nitrogen Doping on the Optical Properties of Carbon Dots Synthesized from Citric Acid. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:1344. [PMID: 37110929 PMCID: PMC10141696 DOI: 10.3390/nano13081344] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/07/2023] [Accepted: 04/09/2023] [Indexed: 06/19/2023]
Abstract
The differences between bare carbon dots (CDs) and nitrogen-doped CDs synthesized from citric acid as a precursor are investigated, aiming at understanding the mechanisms of emission and the role of the doping atoms in shaping the optical properties. Despite their appealing emissive features, the origin of the peculiar excitation-dependent luminescence in doped CDs is still debated and intensively being examined. This study focuses on the identification of intrinsic and extrinsic emissive centers by using a multi-technique experimental approach and computational chemistry simulations. As compared to bare CDs, nitrogen doping causes the decrease in the relative content of O-containing functional groups and the formation of both N-related molecular and surface centers that enhance the quantum yield of the material. The optical analysis suggests that the main emission in undoped nanoparticles comes from low-efficient blue centers bonded to the carbogenic core, eventually with surface-attached carbonyl groups, the contribution in the green range being possibly related to larger aromatic domains. On the other hand, the emission features of N-doped CDs are mainly due to the presence of N-related molecules, with the computed absorption transitions calling for imidic rings fused to the carbogenic core as the potential structures for the emission in the green range.
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Affiliation(s)
- Chiara Olla
- Department of Physics, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, Italy
| | - Antonio Cappai
- Department of Physics, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, Italy
| | - Stefania Porcu
- Department of Physics, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, Italy
| | - Luigi Stagi
- Laboratory of Materials Science and Nanotechnology, CR-INSTM, Department of Chemical, Physics, Mathematics and Natural Sciences, University of Sassari, Via Vienna 2, 07100 Sassari, Italy
| | - Marzia Fantauzzi
- Department of Chemistry and Geological Science, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, Italy
| | - Maria Francesca Casula
- Department of Mechanical, Chemical, and Materials Engineering, CINSA and INSTM, University of Cagliari, Via Marengo 2, I-09123 Cagliari, Italy
| | - Francesca Mocci
- Department of Chemistry and Geological Science, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, Italy
| | - Riccardo Corpino
- Department of Physics, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, Italy
| | - Daniele Chiriu
- Department of Physics, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, Italy
| | - Pier Carlo Ricci
- Department of Physics, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, Italy
| | - Carlo Maria Carbonaro
- Department of Physics, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, Italy
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Green synchronous spectrofluorimetric method for the simultaneous determination of agomelatine and venlafaxine in human plasma at part per billion levels. Sci Rep 2022; 12:22559. [PMID: 36581643 PMCID: PMC9800581 DOI: 10.1038/s41598-022-26827-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 12/20/2022] [Indexed: 12/31/2022] Open
Abstract
A novel sustainable, simple, sensitive, and green spectrofluorimetric method was developed for the concurrent estimation of venlafaxine and agomelatine in pharmaceuticals and biological fluids. The method relies on synchronous fluorescence spectroscopy, where venlafaxine and agomelatine were measured at 276 and 328 nm, respectively, using Δλ of 20 nm. The potential factors affecting the fluorescence intensity were optimized by the one-factor-at-a-time (OFAT) strategy, where synchronous fluorescence intensity was significantly enhanced using a 1% w/v sodium dodecyl sulfate micellar system. The method was fully validated and exhibited excellent linearity (r2 > 0.999 for both drugs) with very low limits of detection (LODs) in the range of 0.14-0.84 ng/mL. Consequently, the proposed approach was efficiently adopted to analyze the co-administered drugs in their pharmaceuticals and in spiked human plasma with excellent % recovery between 97.4 and 102.2%. Finally, the method's greenness was evaluated using different metric tools, including Green Analytical Procedure Index (GAPI) and Analytical GREEnness (AGREE), which proved its excellent greenness.
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Wang L, Zhang W, Shao Y, Zhang D, Guo G, Wang X. Analytical methods for obtaining binding parameters of drug–protein interactions: A review. Anal Chim Acta 2022; 1219:340012. [DOI: 10.1016/j.aca.2022.340012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 11/30/2022]
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