Article
Spectroscopy
Haitham K. R. Al-Sharifi, Ani Deepthi
Summary: Mechanistic studies were conducted on the fluorescence quenching of 2-(2-chloro-12-oxoindolo[2,1-b]quinazolin-6(12H)-ylidene) malononitrile (2CTMA) with aniline in solvent mixtures of acetonitrile and 1,4-dioxane at room temperature, using steady-state and time-resolved methods. It was determined that both dynamic and static quenching processes play a role in the bimolecular quenching reactions, as confirmed by the sphere of action static quenching model and finite sink approximation model.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Environmental Sciences
Vrushali Vinayak Kadam, Raj Mohan Balakrishnan, Jagadeeshbabu Ponnan Ettiyappan
Summary: The study demonstrated the successful synthesis of beta-cyclodextrin-functionalized zinc oxide quantum dots for selective detection of BPA, showing a good linear correlation between fluorescence intensity and BPA concentration under optimal conditions with a low detection limit below the toxic limits in aquatic biota. The fluorescence-based detection of BPA is attributed to the electron transfer mechanism, as explained in scientific literature.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Chemistry, Physical
Muhammad Adnan, Haidi D. Fiedler, Javed Ali, Muhammad Idrees
Summary: The interaction between pyrene and Fe3+, Cu2+, Cr3+, Ni2+, Pb2+ was studied in 0.02 mol L-1 SDS. All studied heavy metal ions reduced the fluorescence intensity of pyrene, although the level of quenching varied. The quenching of pyrene by heavy metal ions was fitted to the Stern-Volmer equation. The Stern-Volmer constants (K-SV) were obtained, indicating the level of quenching and the sensitivity of the method. The method of pyrene fluorescence quenching by heavy metal ions is a fruitful approach for their determination in environmental samples.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Spectroscopy
Naira A. Farid, Nadia F. Youssef, Hisham E. Abdellatef, Yasmine A. Sharaf
Summary: Green spectrofluorimetric methods were developed for the determination of Mirabegron (MG) in pure drug and pharmaceutical dosage form by utilizing the fluorescence quenching effect of MG on tyrosine and L-tryptophan amino acids. The methods demonstrated good correlation coefficients and low detection limits, making them suitable for quality control labs. The quenching mechanism was investigated, and the greenness profile of the methods was assessed. The results showed dynamic quenching for tyrosine and static quenching for L-tryptophan.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Chemistry, Physical
Syed Abbas Raza, Syeda Qurat Naqvi, Anwar Usman, James Robert Jennings, Ying Woan Soon
Summary: The study demonstrates the formation of an RhB-graphene complex, with graphene effectively quenching RhB fluorescence. Analysis suggests a combination of static and dynamic quenching mechanisms, with static quenching due to complex formation likely dominating the observed quenching. Consideration of FRET parameters and thermodynamics suggests the potential of RhB and graphene as a promising donor-acceptor pair for emerging photovoltaics.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2021)
Article
Chemistry, Analytical
Svetlana A. Mescheryakova, Ivan S. Matlakhov, Pavel D. Strokin, Daniil D. Drozd, Irina Yu. Goryacheva, Olga A. Goryacheva
Summary: Doxorubicin (DOX) is a commonly used anti-tumor drug in chemotherapy, but it has high cardio-, neuro- and cytotoxicity. Therefore, continuous monitoring of DOX concentrations in biofluids and tissues is important. This study demonstrates the capabilities of analytical nanosensors based on the quenching of fluorescence of alloyed CdZnSeS/ZnS quantum dots (QDs) for operative DOX detection. Optimized turn-off fluorescence nanosensors were developed for direct DOX determination in undiluted human plasma.
Article
Spectroscopy
Esra Oguzcan, Zeynep Koksal, Tugba Taskin-Tok, Ayse Uzgoren-Baran, Nuriye Akbay
Summary: The interaction type between modafinil and calf thymus DNA was examined using various methods, and the results suggest that modafinil can quench the fluorescence of DNA through both static and dynamic mechanisms. The binding of modafinil with DNA was found to be intercalation, and the docking studies showed that R-modafinil interacts better with DNA. The thermodynamic analysis indicated that the driving forces for the interaction are likely hydrogen bonding or van der Waals forces.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Materials Science, Multidisciplinary
Sonali Mehra, Abhishek K. Chauhan, Shreya Dodeja, Pankaj Kumar, Lalit Goswami, Govind Gupta, A. K. Srivastava, Shailesh Narain Sharma
Summary: This article synthesizes MAPbI3, MAPbICl2, and MAPbIClBr perovskites by one-step and two-step spin-coating methods and investigates their structural and optoelectronic properties. The charge transfer and energy transfer characteristics of perovskite nano crystals passivated by N, N-DMF dissolved in MEH-PPV polymer are also studied. The results show that MAPbI3 perovskite exhibits effective photoluminescence quenching, while energy transfer dominates in degraded composite materials.
Article
Biochemical Research Methods
Muhammad Idrees, Abdul Salam, Munsif Khan
Summary: The interactions between a group of selected phenols (picric acid, p-Nitrophenol, m-Nitrophenol, o-Nitrophenol, and phenol) and the fluorescent probe carbazole in a micellar system of CTAB were studied. The optimal concentration of CTAB for maximum quenching of carbazole was determined for each studied phenol. The quenching of carbazole was observed in both CTAB concentrations, with lower CTAB concentration resulting in higher quenching. The sensitivity of the method, determined by Stern-Volmer constants (K-sv), followed the order picric acid > phenol > m-Nitrophenol > p-Nitrophenol > o-Nitrophenol. The detection threshold (DT) and quantification threshold (QT) were observed in the ranges of 1.76 x 10(-7) - 6.30 x 10(-7) mol/dm(3) and 5.898 x 10(-7) - 2.11 x 10(-6) mol/dm(3) respectively. This method is reproducible and effective for determining the studied phenols in samples.
JOURNAL OF FLUORESCENCE
(2023)
Article
Biochemical Research Methods
Muhammad Idrees, Shah Hussain, Abdul Salam
Summary: The fluorescence quenching of phenanthrene in the anionic micellar system of sodium dodecyl sulphate (SDS) was investigated as a sensitive and selective method for a specific group of aldehydes. The experiments were conducted in a 0.02 mol L-1 SDS solution. All the studied aldehydes showed fluorescence quenching of the probe (phenanthrene). The Stern-Volmer equation was used to explain the phenanthrene quenching by the aldehydes, and the Stern-Volmer constants (K-SV) were obtained to evaluate the sensitivity of the method for the aldehydes. The phenanthrene fluorescence quenching by the aldehydes is valuable for their determination in environmental samples.
JOURNAL OF FLUORESCENCE
(2023)
Article
Chemistry, Physical
Cassia A. Marquezin, M. Teresa Lamy, Eduardo S. de Souza
Summary: This study discusses molecular interactions in a lipid membrane using fluorescence spectroscopy data, and focuses on the fluorescence quenching mechanisms between Laurdan and 2-TSC. Results show that FRET is responsible for the non-radiative deexcitation of Laurdan in the presence of 2-TSC, providing insights into the localization of molecules in lipid membranes.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Biochemical Research Methods
Muhammad Naeem Khan, Syeda Qandeel Wajid Kazmi
Summary: This study used fluorescence-based techniques to examine the interaction between L-tryptophan and a selection of aldehydes. The results showed that all five aldehydes induced quenching of L-tryptophan's fluorescence intensity. The study also determined Stern-Volmer constants and detection limits for the investigated aldehydes. The findings have implications for the development of sensors and the analysis of aldehydes in environmental and biological samples.
JOURNAL OF FLUORESCENCE
(2023)
Article
Biochemical Research Methods
Muhammad Idrees, Abdul Salam
Summary: The study investigated the interaction of pyrene with selected amines in aqueous sodium dodecyl sulfate, revealing pyrene's ability to act as a sensitive sensor for detecting amines in environmental samples. Different concentrations of SDS were tested to determine the optimum conditions for maximum quenching and detection limits of pyrene. Stern-Volmer equation was used to calculate Stern-Volmer constants, reflecting pyrene's sensitivity towards the studied amines, with Benzylamine showing the highest sensitivity amongst the tested amines.
JOURNAL OF FLUORESCENCE
(2021)
Article
Chemistry, Physical
Serguei Feskov, Stanislav L. Bondarev, Tamara F. Raichenok, Sergei A. Tikhomirov, Anatoly I. Ivanov
Summary: A theory is developed to explain the fluorescence quenching of a centrosymmetric acridine-dione derivative induced by H-bonding interactions with solvents in mixtures of methanol and dimethylformamide. The theory considers both dynamic and static mechanisms of the quenching and explains the threshold-type dependence of the quenching efficiency on the concentration of methanol. A model of H-bond clustering in alcohol and H-bond-accepting solvent mixtures is proposed, which provides a quantitative description of the observed fluorescence yield and kinetics.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Chemistry, Physical
Antoine Juneau, Taylor O. Hope, Jason Malenfant, Mihai Mesko, Jacob McNeill, Mathieu Frenette
Summary: Visible light photoredox catalysts are widely used in organic synthesis, and DFT can be used as a predictive tool for determining reactivity. Kinetics play a crucial role in the success of photoredox reactions.