Determination of quantum yields for various processes (such as fluorescence and triplet formation) in dye-loaded light-scattering powdered samples is an open issue. Here, we report the testing of laser-induced optoacoustic spectroscopy (LIOAS) for the determination of fluorescence quantum yields of Rhodamine 101 and Rhodamine 6G adsorbed at various loadings on microgranular cellulose powder. The results of the LIOAS experiments are consistent with those from the method developed in one of our laboratories based on the measurement of apparent reflectance using an integrating sphere [Mirenda, M.; Lagorio, M. G.; San Roman, E. Langmuir 2004, 20, 3690-3697], which allows the simultaneous calculation of fluorescence quantum yield and reflectance devoid of fluorescence artifacts. Criteria to quantify overall errors and detect outlying values are developed. The theory underlying the application of LIOAS to light-scattering samples and experimental details are presented.
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Heliyon
January 2025
Transmission Electronic Microscopy Laboratory, Electronic Microscopy Unit, Department of Biology, University of Cauca, Popayán, 190002, Colombia.
A green methodology for the synthesis of carbon quantum dots (CQDs) from coffee husk without the use of any toxic solvents is proposed in this work. Sonochemical exfoliation of biochar, obtained from the thermal carbonization of coffee husk (from a certified coffee seeds) at low temperature in an air-restricted atmosphere, is described as an alternative procedure for the sustainable production of CQDs. The synthesized CQDs exhibited blue fluorescence with a strong maximum emission band at 410 nm when excited at a maximum absorption wavelength of 330 nm.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Quantum-Si, Guilford, CT, USA.
Single-molecule fluorescence resonance energy transfer (smFRET) is a powerful technique for studying the structural dynamics of protein molecules or detecting interactions between protein molecules in real time. Due to the high sensitivity in spatial and temporal resolution, smFRET can decipher sub-populations within heterogeneous native state conformations, which are generally lost in traditional measurements due to ensemble averaging. In addition, the single-molecule reconstitution allows protein molecules to be observed for an extensive period of time and can recapitulate the geometry of the cellular environment to retain biological function.
View Article and Find Full Text PDFMethods Appl Fluoresc
January 2025
Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, No.36 Sanhao Street, Heping District, Shenyang, Liaoning Province, China, Shenyang, 110004, CHINA.
Molybdenum disulfide quantum dots (MoS2 QDs) is a new type of graphite like nanomaterial, which exhibited well chemical stability, unique fluorescence characteristics, and excellent biocompatibility. The conventional hydrothermal synthesis of MoS2 generally requires a long-term reaction at high temperature and high pressure. Herein, we have developed a simple and fast MoS2 QDs synthesis scheme using microwave heating, and further modified the surface of MoS2 QDs using 3-aminophenylboronic acid.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Department of Clinical Laboratory Medicine, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510000, China.
Immunochromatographic assays (ICAs) provide simple and rapid strategies for bacterial diagnosis but still suffer from the problems of low sensitivity and high dependency on paired antibodies. Herein, the broad-spectrum capture and detection capability of the antibody-free electropositive nanoprobe are clarified for bacteria for the first time and an ultrasensitive fluorescent ICA platform is constructed for the simultaneous diagnosis of multiple pathogens. A magnetic multilayer quantum dot nanocomposite with an amino-embedded SiO shell (MagMQD@Si) is designed to enrich bacteria from solutions effectively, offer high luminescence, and reduce background signals on test strips, thus greatly improving the sensitivity and stability of ICA technique for pathogen.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Jihua Hengye Electronic Materials Co. Ltd., Foshan, Guangdong, 528200, P. R. China.
B- and N-heterocyclic fluorophores have reveal promising efficiency in blue organic light-emitting diodes (OLEDs) with small full-width-at-half-maximum (FWHM). However, their structural determinants for spectral broadening and operating stability are still needed to be investigated in further. Herein, a novel multi-N-heterocycles Diindolo[3,2,1jk:3',2',1'jk]dicarbazole[1,2-b:4,5-b] (DIDCz) is proposed to manipulate the emission color toward pure blue region by extending π-conjugation of the N-π-N bridge.
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