Methods and Applications in Fluorescence最新文献_第4页

Development of an analytical method for the determination of pesticides in tropical fruits by LC-QTOF-MS/MS after QuEChERS extraction sample cleanup and DLLME preconcentration. 建立了QuEChERS提取、样品清洗、DLLME预富集的LC-QTOF-MS/MS分析热带水果中农药的方法。

IF 3.2 3区化学

Methods and Applications in Fluorescence Pub Date : 2023-11-23 DOI: 10.1088/2050-6120/ad0bfe

Sabriye Sel, Elif Öztürk Er, İkbal Koyuncu

{"title":"Development of an analytical method for the determination of pesticides in tropical fruits by LC-QTOF-MS/MS after QuEChERS extraction sample cleanup and DLLME preconcentration.","authors":"Sabriye Sel, Elif Öztürk Er, İkbal Koyuncu","doi":"10.1088/2050-6120/ad0bfe","DOIUrl":"10.1088/2050-6120/ad0bfe","url":null,"abstract":"In this study, QuEChERS extraction was combined with dispersive liquid-liquid microextraction (DLLME) to extract pesticides from tropical fruits for determination by a highly accurate and sensitive liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS/MS) system. The QuEChERS method served as a matrix clean-up tool and the DLLME method preconcentrated the analytes for their determination at trace levels. All parameter variables of the DLLME method were optimized to improve the extraction output and lower the limits of detection and quantification (LOD and LOQ) for all the analytes. Under the optimum experimental conditions, the LOD and LOQ values were found in the range of 0.004-0.013 and 0.27-0.61μg l-1, respectively. The detection limits achieved by direct LC-QTOF-MS/MS analysis were increased by about 10-260 folds using the optimized DLLME method. To assess the accuracy and applicability of the developed method, spike recovery experiments on tropical fruits were carried out. The matrix matching calibration method was used to enhance the quantification accuracy of the analytes in kiwi, pineapple, and mango matrices, with percent recoveries ranging between 89 and 117%.","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92155330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analysis of the fluorescent properties of vaginal fluid upon ageing. 阴道液老化后的荧光特性分析。

IF 3.2 3区化学

Methods and Applications in Fluorescence Pub Date : 2023-11-09 DOI: 10.1088/2050-6120/ad06dd

Judith de Vos, Rosa E Otto, Nihad Achetib, Anas Gasser, Maurice C G Aalders, Annemieke van Dam

{"title":"Analysis of the fluorescent properties of vaginal fluid upon ageing.","authors":"Judith de Vos, Rosa E Otto, Nihad Achetib, Anas Gasser, Maurice C G Aalders, Annemieke van Dam","doi":"10.1088/2050-6120/ad06dd","DOIUrl":"10.1088/2050-6120/ad06dd","url":null,"abstract":"Detection and identification of body fluids are crucial aspects of forensic investigations, aiding in crime scene reconstructions and providing important leads. Although many methods have been developed for these purposes, no method is currently in use in the forensic field that allows rapid, non-contact detection and identification of vaginal fluids directly at the crime scene. The development of such technique is mainly challenged by the complex chemistry of the constituents, which can differ between donors and exhibits changes based on woman's menstrual cycle. The use of fluorescence spectroscopy has shown promise in this area for other biological fluids. Therefore, the aim of this study was to identify specific fluorescent signatures of vaginal fluid with fluorescence spectroscopy to allow on-site identification. Additionally, the fluorescent properties were monitored over time to gain insight in the temporal changes of the fluorescent spectra of vaginal fluid. The samples were excited at wavelengths ranging from 200 to 600 nm and the induced fluorescence emission was measured from 220 to 700 nm. Excitation and emission maps (EEMs) were constructed for eight donors at seven time points after donation. Four distinctive fluorescence peaks could be identified in the EEMs, indicating the presence of proteins, fluorescent oxidation products (FOX), and an unidentified component as the dominant contributors to the fluorescence. To further asses the fluorescence characteristics of vaginal fluid, the fluorescent signatures of protein and FOX were used to monitor protein and lipid oxidation reactions over time. The results of this study provide insights into the intrinsic fluorescent properties of vaginal fluid over time which could be used for the development of a detection and identification method for vaginal fluids. Furthermore, the observed changes in fluorescence signatures over time could be utilized to establish an accurate ageing model.","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50162147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Paper test strip for fluorescence detection of iron ion based on nitrogen, zinc and copper codoped carbon dots. 基于氮、锌、铜共掺杂碳点的铁离子荧光检测纸试纸条。

IF 3.2 3区化学

Methods and Applications in Fluorescence Pub Date : 2023-11-03 DOI: 10.1088/2050-6120/ad0648

Dou Yang, Shuhan Jiang, Shuai Zhang, Xiaoyu Fan, Xiaodong Shao, Shuhao Wang, Rui Li, Qiaoli Yue

{"title":"Paper test strip for fluorescence detection of iron ion based on nitrogen, zinc and copper codoped carbon dots.","authors":"Dou Yang, Shuhan Jiang, Shuai Zhang, Xiaoyu Fan, Xiaodong Shao, Shuhao Wang, Rui Li, Qiaoli Yue","doi":"10.1088/2050-6120/ad0648","DOIUrl":"10.1088/2050-6120/ad0648","url":null,"abstract":"In this study, a test strip for fluorometric analysis of iron ion (Fe3+) was constructed based on nitrogen, zinc and copper codoped carbon dots (NZC-CDs) as fluorescence probes. NZC-CDs were synthesized by hydrothermal method. The morphology, size, components, crystal state and optical properties of NZC-CDs were characterized by transmission electron microscope (TEM), Fourier-transform infrared (FT-IR), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), UV-vis absorption and fluorescence spectroscopy techniques, respectively. NZC-CDs exhibited bright blue fluorescence under UV lamp with a quantum yield at 17.76%. The fluorescence of NZC-CDs was quenched by Fe3+possibly due to the static quenching. The possible fluorescence quenching mechanism was also discussed. The quenching fluorescence was linear with the concentration of Fe3+in the range of 2.5-400μM with a low detection limit of 0.5μM. For the convenient detection, the test strips based on filter paper were employed for Fe3+assay. Moreover, the present approach was successfully applied in the determination of Fe3+in real samples including black fungus, duck blood and pork liver. The sensing method had the potential application in more food analysis.","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50158320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of annealing on the room temperature luminescence of coumarin 106 in PVA films. 退火对香豆素106在PVA膜中室温发光的影响。

IF 3.2 3区化学

Methods and Applications in Fluorescence Pub Date : 2023-11-02 DOI: 10.1088/2050-6120/ad06dc

Emma Alexander, Luca Ceresa, Danh Pham, Zygmunt Gryczynski, Ignacy Gryczynski

{"title":"Effect of annealing on the room temperature luminescence of coumarin 106 in PVA films.","authors":"Emma Alexander, Luca Ceresa, Danh Pham, Zygmunt Gryczynski, Ignacy Gryczynski","doi":"10.1088/2050-6120/ad06dc","DOIUrl":"10.1088/2050-6120/ad06dc","url":null,"abstract":"We studied the effect of annealing on the luminescence of Coumarin 106 (C106) in poly (vinyl alcohol) films (PVA films). The samples and reference polymer films were treated at temperatures between 100 °C and 150 °C (212 F and 302 F) for various times. After cooling and smoothing, the samples and references were measured at room temperature. We observed that the PVA polymer (reference films) changes its optical properties with annealing at higher temperatures, affecting the baselines in absorption and the backgrounds in emission measurements. This requires precise background subtractions and control of the signal-to-noise ratio. Whereas the fluorescence intensity of C106 in PVA films modestly decreases with annealing, the phosphorescence depends dramatically and progressively increases by many folds. The fluorescence quantum yields and lifetimes decrease with the annealing, which suggests an increase in the non-radiative processes in the singlet excited state S1. The increase in the phosphorescence intensities results from increased intersystem crossing (ISC), which also decreases fluorescence. We also studied the effect of annealing on phosphorescence with the directly excited triplet state of C106. In this case, two processes are affected by annealing, S0→T1absorption and T1→S0phosphorescence. The long-wavelength excitation (475 nm) avoids PVA polymer excitation. The phosphorescence lifetime decreases with annealing while the phosphorescence intensity increases. These changes suggest that the radiative rate of T1→ S0increases with annealing.","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50162148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ratiometric fluorescence detection of the angiotensin-converting enzyme via single-excitation and double-emission biomass-derived carbon quantum dots. 通过单激发和双发射生物质衍生的碳量子点对血管紧张素转换酶进行定量荧光检测。

IF 3.2 3区化学

Methods and Applications in Fluorescence Pub Date : 2023-10-25 DOI: 10.1088/2050-6120/ad02dd

Zhihua Zhan, Huihui Mao, Mingyue Xue, Guocheng Han, Guohua Zhou, Ying Zhang

{"title":"Ratiometric fluorescence detection of the angiotensin-converting enzyme via single-excitation and double-emission biomass-derived carbon quantum dots.","authors":"Zhihua Zhan, Huihui Mao, Mingyue Xue, Guocheng Han, Guohua Zhou, Ying Zhang","doi":"10.1088/2050-6120/ad02dd","DOIUrl":"10.1088/2050-6120/ad02dd","url":null,"abstract":"Efficient and rapid detection of angiotensin-converting enzyme (ACE) activity is important for preventing hypertension and the discovery of new angiotensin-converting enzyme inhibitors (ACEI). In this work, a single-excitation and double-emission biomass-derived carbon quantum dots (CQDs) was prepared and applied for ratiometric fluorescence detection of ACE. Fresh banyan leaves were extracted with ethanol and acetone, and the extracted solution was used as the precursor to produce the carbon quantum dots (BL-CQDs) with single-excitation and double-emission properties. The synthesized BL-CQDs is about 1.7 nm, has a graphene-like structure, contains a variety of hydrophilic functional groups on the surface, and has good fluorescence properties. Its fluorescence intensity ratio (I677/I460) is linear with ACE activity in the range of 0.02-0.8 U l-1. The regression equation is△F=2.5371CACE-0.0311. The method was successfully applied to the determination of ACE activity in pig lung and human serum, and the inhibitory efficiency of the flavonoid extract and captopril tablets on ACE activity was also investigated, which can be applied to the screening of ACEI. The survival rate and fluorescence imaging of Bel-7404 cells under the condition of high concentration BL-CQDs showed BL-CQDs had low cytotoxicity and good biocompatibility. These results indicate that the BL-CQDs can be used as an excellent fluorescent probe, providing a new method for screening ACE activity and plant-derived ACEI.","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41205100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A new twist on PIFE: photoisomerisation-related fluorescence enhancement. PIFE的一个新转折：与光异构化相关的荧光增强。

IF 2.4 3区化学

Methods and Applications in Fluorescence Pub Date : 2023-10-12 DOI: 10.1088/2050-6120/acfb58

Evelyn Ploetz, Benjamin Ambrose, Anders Barth, Richard Börner, Felix Erichson, Achillefs N Kapanidis, Harold D Kim, Marcia Levitus, Timothy M Lohman, Abhishek Mazumder, David S Rueda, Fabio D Steffen, Thorben Cordes, Steven W Magennis, Eitan Lerner

{"title":"A new twist on PIFE: photoisomerisation-related fluorescence enhancement.","authors":"Evelyn Ploetz, Benjamin Ambrose, Anders Barth, Richard Börner, Felix Erichson, Achillefs N Kapanidis, Harold D Kim, Marcia Levitus, Timothy M Lohman, Abhishek Mazumder, David S Rueda, Fabio D Steffen, Thorben Cordes, Steven W Magennis, Eitan Lerner","doi":"10.1088/2050-6120/acfb58","DOIUrl":"10.1088/2050-6120/acfb58","url":null,"abstract":"PIFE was first used as an acronym for protein-induced fluorescence enhancement, which refers to the increase in fluorescence observed upon the interaction of a fluorophore, such as a cyanine, with a protein. This fluorescence enhancement is due to changes in the rate ofcis/transphotoisomerisation. It is clear now that this mechanism is generally applicable to interactions with any biomolecule. In this review, we propose that PIFE is thereby renamed according to its fundamental working principle as photoisomerisation-related fluorescence enhancement, keeping the PIFE acronym intact. We discuss the photochemistry of cyanine fluorophores, the mechanism of PIFE, its advantages and limitations, and recent approaches to turning PIFE into a quantitative assay. We provide an overview of its current applications to different biomolecules and discuss potential future uses, including the study of protein-protein interactions, protein-ligand interactions and conformational changes in biomolecules.","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10570931/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41134017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of MSD analysis from single particle tracking with MSD from images. Getting the best of both worlds. 来自单粒子跟踪的MSD分析与来自图像的MSD的比较。两全其美。

IF 3.2 3区化学

Methods and Applications in Fluorescence Pub Date : 2023-10-12 DOI: 10.1088/2050-6120/acfd7e

Constanza Kettmayer, Enrico Gratton, Laura C Estrada

{"title":"Comparison of MSD analysis from single particle tracking with MSD from images. Getting the best of both worlds.","authors":"Constanza Kettmayer, Enrico Gratton, Laura C Estrada","doi":"10.1088/2050-6120/acfd7e","DOIUrl":"10.1088/2050-6120/acfd7e","url":null,"abstract":"Fluorescence microscopy can provide valuable information about cell interior dynamics. Particularly, mean squared displacement (MSD) analysis is widely used to characterize proteins and sub-cellular structures' mobility providing the laws of molecular diffusion. The MSD curve is traditionally extracted from individual trajectories recorded by single-particle tracking-based techniques. More recently, image correlation methods like iMSD have been shown capable of providing averaged dynamic information directly from images, without the need for isolation and localization of individual particles. iMSD is a powerful technique that has been successfully applied to many different biological problems, over a wide spatial and temporal scales. The aim of this work is to review and compare these two well-established methodologies and their performance in different situations, to give an insight on how to make the most out of their unique characteristics. We show the analysis of the same datasets by the two methods. Regardless of the experimental differences in the input data for MSD or iMSD analysis, our results show that the two approaches can address equivalent questions for free diffusing systems. We focused on studying a range of diffusion coefficients between D = 0.001μm2s-1and D = 0.1μm2s-1, where we verified that the equivalence is maintained even for the case of isolated particles. This opens new opportunities for studying intracellular dynamics using equipment commonly available in any biophysical laboratory.","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41136166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Emission color tuning and dual-mode luminescence thermometry design in Dy³⁺/Eu³⁺co-doped SrMoO₄phosphors. Dy3+/Eu3+共掺杂SrMoO4磷的发射颜色调谐和双模发光测温设计。

IF 3.2 3区化学

Methods and Applications in Fluorescence Pub Date : 2023-10-12 DOI: 10.1088/2050-6120/acf97b

Vaibhav Chauhan, Prashant Dixit, Prashant Kumar Pandey, Satyam Chaturvedi, Praveen Chandra Pandey

{"title":"Emission color tuning and dual-mode luminescence thermometry design in Dy3+/Eu3+co-doped SrMoO4phosphors.","authors":"Vaibhav Chauhan, Prashant Dixit, Prashant Kumar Pandey, Satyam Chaturvedi, Praveen Chandra Pandey","doi":"10.1088/2050-6120/acf97b","DOIUrl":"10.1088/2050-6120/acf97b","url":null,"abstract":"The challenge of building a highly reliable contactless temperature probe with high sensitivity, good temperature-induced color discriminability, and economical synthesis has prompted the research community to work in the field of rare-earth-based luminescence thermometry. Moreover, the fast-growing market for optoelectronic devices has increased the demand for tunable color-emitting phosphors. In this study, Dy3+/Eu3+co-doped SrMoO4phosphors were developed as tunable color-emitting source and dual-mode luminescence thermometer. A facile and cost-effective auto-combustion method was used to synthesize the phosphors. Our work demonstrates a viable scheme for tailoring the emission of single-phase phosphors by precisely controlling the dopant concentrations and by modulating excitation wavelength. The overall emission is tuned from greenish-yellow to white and greenish-yellow to reddish-orange. A detailed energy transfer process from the host to the Ln3+ions and between the Ln3+ions is discussed. Further, anti-thermal quenching in the emission of Dy3+ion is observed when excited with 297 nm. The dual-mode luminescence thermometry has been studied by analyzing the fluorescence intensity ratio of Dy3+and Eu3+ions upon excitation at 297 nm. The maximum relative sensitivity value for 4% Eu3+co-doped SrMoO4:4%Dy3+phosphor is 1.46% K-1at 300 K. Furthermore, the configurational coordinate diagram is presented to elucidate the nature of temperature-dependent emission. Therefore, our research opens up new avenues for the development of color-tunable luminescent materials for various optoelectronic and temperature-sensing applications.","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10579783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Carbon dots derived from citric acid and urea as fluorometric probe for determining melamine contamination in infant formula sample. 柠檬酸和尿素衍生的碳点作为荧光探针，用于测定婴儿配方奶粉样品中的三聚氰胺污染。

IF 3.2 3区化学

Methods and Applications in Fluorescence Pub Date : 2023-10-12 DOI: 10.1088/2050-6120/acf547

Souliyanh Phimmasone, Pornthip Boonsri, Weena Siangproh, Nuanlaor Ratanawimarnwong, Piyada Jittangprasert, Thitirat Mantim, Nunticha Limchoowong, Kriangsak Songsrirote

{"title":"Carbon dots derived from citric acid and urea as fluorometric probe for determining melamine contamination in infant formula sample.","authors":"Souliyanh Phimmasone, Pornthip Boonsri, Weena Siangproh, Nuanlaor Ratanawimarnwong, Piyada Jittangprasert, Thitirat Mantim, Nunticha Limchoowong, Kriangsak Songsrirote","doi":"10.1088/2050-6120/acf547","DOIUrl":"10.1088/2050-6120/acf547","url":null,"abstract":"Melamine has been intentionally added into food products to increase the protein count at less cost, especially in dairy products for infant resulting in serious adverse effects on health of consumers. Therefore, this study aimed to develop a method to quantify melamine in dairy products based on the change of fluorescent properties of carbon dots (CDs) as sensing probe. CDs with green-fluorescent emission were synthesized from citric acid and urea under microwave irradiation. The synthesized CDs emitted fluorescence at the maximum wavelength of 538 nm with excitation wavelength of 410 nm. Thus, they provided high sensitivity and selectivity on melamine detection by which fluorescent emission of the CDs was increasingly quenched upon increasing melamine concentrations. Optimal conditions for melamine determination using the CDs was under pH 6, volume ratio between CDs and sample of 2:8 and reaction time of 15 min. The developed method provided high precision of melamine determination with less than 5% of %RSD (n = 5), wide detection range from 1.0 to 200.0 ppm, and high sensitivity with limit of detection (LOD) of 0.47 ppm and limit of quantification (LOQ) of 1.56 ppm, which is within the regulated level by the Food and Drug Administration of the United States for melamine in dairy products. Several analytical characterization techniques were conducted to elucidate the reaction mechanism between CDs and melamine, and the hydrogen bonding interaction was proposed.","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10118813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Photo-physical characterization of high triplet yield brominated fluoresceins by transient state (TRAST) spectroscopy. 通过瞬态（TRAST）光谱对高三重产率溴化荧光素的光物理表征。

IF 3.2 3区化学

Methods and Applications in Fluorescence Pub Date : 2023-10-03 DOI: 10.1088/2050-6120/acfb59

Baris Demirbay, Glib Baryshnikov, Martin Haraldsson, Joachim Piguet, Hans Ågren, Jerker Widengren

{"title":"Photo-physical characterization of high triplet yield brominated fluoresceins by transient state (TRAST) spectroscopy.","authors":"Baris Demirbay, Glib Baryshnikov, Martin Haraldsson, Joachim Piguet, Hans Ågren, Jerker Widengren","doi":"10.1088/2050-6120/acfb59","DOIUrl":"https://doi.org/10.1088/2050-6120/acfb59","url":null,"abstract":"Photo-induced dark transient states of fluorophores can pose a problem in fluorescence spectroscopy. However, their typically long lifetimes also make them highly environment sensitive, suggesting fluorophores with prominent dark-state formation yields to be used as microenvironmental sensors in bio-molecular spectroscopy and imaging. In this work, we analyzed the singlet-triplet transitions of fluorescein and three synthesized carboxy-fluorescein derivatives, with one, two or four bromines linked to the anthracence backbone. Using transient state (TRAST) spectroscopy, we found a prominent internal heavy atom (IHA) enhancement of the intersystem crossing (ISC) rates upon bromination, inferred by density functional theory calculations to take place via a higher triplet state, followed by relaxation to the lowest triplet state. A corresponding external heavy atom (EHA) enhancement was found upon adding potassium iodide (KI). Notably, increased KI concentrations still resulted in lowered triplet state buildup in the brominated fluorophores, due to relatively lower enhancements in ISC, than in the triplet decay. Together with an antioxidative effect on the fluorophores, adding KI thus generated a fluorescence enhancement of the brominated fluorophores. By TRAST measurements, analyzing the average fluorescence intensity of fluorescent molecules subject to a systematically varied excitation modulation, dark state transitions within very high triplet yield (>90%) fluorophores can be directly analyzed under biologically relevant conditions. These measurements, not possible by other techniques such as fluorescence correlation spectroscopy, opens for bio-sensing applications based on high triplet yield fluorophores, and for characterization of high triplet yield photodynamic therapy agents, and how they are influenced by IHA and EHA effects.","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 4","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41133516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0