Methods and Applications in Fluorescence最新文献

{"title":"Enhanced emission intensity in (Li⁺/Ca²⁺/Bi³⁺) ions co-doped NaLa(MoO₄)₂: Dy³⁺phosphors and their Judd-Ofelt analysis for WLEDs applications.","authors":"Sonali Sonali, C Shivakumara","doi":"10.1088/2050-6120/acbbb9","DOIUrl":"10.1088/2050-6120/acbbb9","url":null,"abstract":"<p><p>In the present study, we have synthesized a series of Dy3+ ion doped NaLa(MoO4)2phosphors by the conventional solid-state method at 750 °C for 4h. All the compounds were crystallized in the tetragonal scheelite type structure with space group (I41/a, No.88). The morphology and functional group were confirmed by the field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared(FTIR)spectroscopy. Upon near-Ultraviolet (n-UV) excitation, the PL spectra exhibit the two characteristic emissions of Dy3+ ions, blue (4F9/2→6H15/2) at 487 nm and yellow (4F9/2→6H13/2) at 574nm respectively. The optimum concentration of Dy3+ionis 3 mol% and then quenching occurred due to multipolar interaction. Further, enhanced the emission intensity by co-doping with monovalent (Li+), divalent (Ca2+) and trivalent (Bi3+) ions. Among them, Li+ ion co-doped samples are shown maximum intensity (50 times) more than Dy3+ doped phosphors as relaxation of parity restriction of electric dipole transition because of local distortion of crystal field around the Dy3+ ions. In addition, by incorporation of Eu3+ ions into NaLa(MoO4)2:Dy3+system, tuned the emission color from white to red, owing to energy transfer from Dy3+ to Eu3+ ions. The intensity parameters (Ω2, Ω4) and radiative properties such as transition probabilities (AT), radiative lifetime (rad), and branching ratio were calculated using the Judd-Ofelt theory. CIE color coordinates, CCT values indicates that these phosphors exhibit an excellent white emission. The determined radiative properties, CIE and CCT results revealed that the Dy3+-activated NaLa(MoO4)2phosphors are potential materials for developing white LEDs, and optoelectronic device fabrications.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9260665","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}

{"title":"Effect of buffers and pH in antenna sensitized Eu(III) luminescence.","authors":"Lea Gundorff Nielsen,&nbsp;Thomas Just Sørensen","doi":"10.1088/2050-6120/acb63a","DOIUrl":"https://doi.org/10.1088/2050-6120/acb63a","url":null,"abstract":"<p><p>The photophysics of a europium(III) complex of 1,4,7,10-tetraazacycododecane-1,4,7-triacetic acid-10-(2-methylene)-1-azathioxanthone was investigated in three buffer systems and at three pH values. The buffers-phosphate buffered saline (PBS), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), and universal buffer (UB)-had no effect on the europium luminescence, but a lower overall emission intensity was determined in HEPES. It was found that this was due to quenching of the 1-azathioxanthone first excited singlet state by HEPES. The effect of pH on the photophysics of the complex was found to be minimal, and protonation of the pyridine nitrogen was found to be irrelevant. Even so, pH was shown to change the intensity ratio between 1-azathioxanthone fluorescence and europium luminescence. It was concluded that the full photophysics of a potential molecular probe should be investigated to achieve the best possible results in any application.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10668377","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}

{"title":"Structural and optical variation of pseudoisocyanine aggregates nucleated on DNA substrates.","authors":"Matthew Chiriboga,&nbsp;Christopher M Green,&nbsp;Divita Mathur,&nbsp;David A Hastman,&nbsp;Joseph S Melinger,&nbsp;Remi Veneziano,&nbsp;Igor L Medintz,&nbsp;Sebastián A Díaz","doi":"10.1088/2050-6120/acb2b4","DOIUrl":"https://doi.org/10.1088/2050-6120/acb2b4","url":null,"abstract":"<p><p>Coherently coupled pseudoisocyanine (PIC) dye aggregates have demonstrated the ability to delocalize electronic excitations and ultimately migrate excitons with much higher efficiency than similar designs where excitations are isolated to individual chromophores. Here, we report initial evidence of a new type of PIC aggregate, formed through heterogeneous nucleation on DNA oligonucleotides, displaying photophysical properties that differ significantly from previously reported aggregates. This new aggregate, which we call the super aggregate (SA) due to the need for elevated dye excess to form it, is clearly differentiated from previously reported aggregates by spectroscopic and biophysical characterization. In emission spectra, the SA exhibits peak narrowing and, in some cases, significant quantum yield variation, indicative of stronger coupling in cyanine dyes. The SA was further characterized with circular dichroism and atomic force microscopy observing unique features depending on the DNA substrate. Then by integrating an AlexaFluor^TM647 (AF) dye as an energy transfer acceptor into the system, we observed mixed energy transfer characteristics using the different DNA. For example, SA formed with a rigid DNA double crossover tile (DX-tile) substrate resulted in AF emission sensitization. While SA formed with more flexible non-DX-tile DNA (i.e. duplex and single strand DNA) resulted in AF emission quenching. These combined characterizations strongly imply that DNA-based PIC aggregate properties can be controlled through simple modifications to the DNA substrate's sequence and geometry. Ultimately, we aim to inform rational design principles for future device prototyping. For example, one key conclusion of the study is that the high absorbance cross-section and efficient energy transfer observed with rigid substrates made for better photonic antennae, compared to flexible DNA substrates.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10362908/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9907988","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}

{"title":"Pulse-shaped broadband multiphoton excitation for single-molecule fluorescence detection in the far field.","authors":"David Nobis,&nbsp;Henry G Sansom,&nbsp;Steven W Magennis","doi":"10.1088/2050-6120/aca87f","DOIUrl":"https://doi.org/10.1088/2050-6120/aca87f","url":null,"abstract":"Multiphoton excitation of fluorescence has many potential advantages over resonant (one-photon) excitation, but the method has not found widespread use for ultrasensitive applications. We recently described an approach to the multiphoton excitation of single molecules that uses a pulse shaper to compress and tailor pulses from an ultrafast broadband laser in order to optimise the brightness and signal-to-background ratio following non-linear excitation. Here we provide a detailed description of the setup and illustrate its use and potential by optimising two-photon fluorescence of a common fluorophore, rhodamine 110, at the single-molecule level. We also show that a DNA oligonucleotide labelled with a fluorescent nucleobase analogue, tC, can be detected using two-photon FCS, whereas one-photon excitation causes rapid photobleaching. The ability to improve the signal-to-background ratio and to reduce the incident power required to attain a given brightness can be applied to the multiphoton excitation of any fluorescent species, from small molecules with low multiphoton cross sections to the brightest nanoparticles.","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9660290","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}

{"title":"Quantity with quality.","authors":"David J S Birch,&nbsp;Marcia Levitus,&nbsp;Yves Mély","doi":"10.1088/2050-6120/aca5f6","DOIUrl":"https://doi.org/10.1088/2050-6120/aca5f6","url":null,"abstract":"","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9591252","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}

{"title":"MINFLUX imaging of a bacterial molecular machine at nanometer resolution.","authors":"Alexander Carsten,&nbsp;Maren Rudolph,&nbsp;Tobias Weihs,&nbsp;Roman Schmidt,&nbsp;Isabelle Jansen,&nbsp;Christian A Wurm,&nbsp;Andreas Diepold,&nbsp;Antonio Virgilio Failla,&nbsp;Manuel Wolters,&nbsp;Martin Aepfelbacher","doi":"10.1088/2050-6120/aca880","DOIUrl":"https://doi.org/10.1088/2050-6120/aca880","url":null,"abstract":"<p><p>The resolution achievable with the established super-resolution fluorescence nanoscopy methods, such as STORM or STED, is in general not sufficient to resolve protein complexes or even individual proteins. Recently, minimal photon flux (MINFLUX) nanoscopy has been introduced that combines the strengths of STED and STORM nanoscopy and can achieve a localization precision of less than 5 nm. We established a generally applicable workflow for MINFLUX imaging and applied it for the first time to a bacterial molecular machine<i>in situ</i>, i.e., the injectisome of the enteropathogen<i>Y. enterocolitica</i>. We demonstrate with a pore protein of the injectisome that MINFLUX can achieve a resolution down to the single molecule level<i>in situ</i>. By imaging a sorting platform protein using 3D-MINFLUX, insights into the precise localization and distribution of an injectisome component in a bacterial cell could be accomplished. MINFLUX nanoscopy has the potential to revolutionize super-resolution imaging of dynamic molecular processes in bacteria and eukaryotes.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10406921","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}

{"title":"Keratin intrinsic fluorescence as a mechanism for non-invasive monitoring of its glycation.","authors":"Rhona Muir,&nbsp;Shareen Forbes,&nbsp;David J S Birch,&nbsp;Vladislav Vyshemirsky,&nbsp;Olaf J Rolinski","doi":"10.1088/2050-6120/aca507","DOIUrl":"https://doi.org/10.1088/2050-6120/aca507","url":null,"abstract":"<p><p>We have studied the evolution of keratin intrinsic fluorescence as an indicator of its glycation. Steady-state and time-resolved fluorescence of free keratin and keratin-glucose samples were detected in PBS solutions<i>in vitro</i>. The changes in the fluorescence response demonstrate that the effect of glucose is manifest in the accelerated formation of fluorescent cross-links with an emission peak at 460 nm and formation of new cross-links with emission peaks at 525 nm and 575 nm. The fluorescence kinetics of these structures is studied and their potential application for the detection of long-term complications of diabetes discussed.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10406920","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}

{"title":"Preparation, AIE and ESIPT behaviour, controllable solid-state fluorescence and application of Co²⁺probe based on<i>α</i>-cyanostilbene.","authors":"Meihui Chen,&nbsp;Wenheng Huang,&nbsp;Yangping Li,&nbsp;Yongchun Chen,&nbsp;Dan Ji,&nbsp;Mingguang Zhu","doi":"10.1088/2050-6120/aca378","DOIUrl":"https://doi.org/10.1088/2050-6120/aca378","url":null,"abstract":"<p><p>A simple<i>α</i>-cyanostilbene-functioned salicylaldehyde-based Schiff-base probe, which exhibited outstanding 'aggregation-induced emission and excited state intramolecular proton transfer (AIE + ESIPT)' emission in solution, aggregation and solid states, was synthesized in high yield of 87%. Its solid-states with different morphologies emitted different fluorescence after crystallization in EtOH/H₂O (1/2, v/v) mixtures or pure EtOH solvent. Besides, it exhibited an obvious spectro-photometrical fluorescence quenching for highly selective sensing of Co²⁺in THF/water system (ƒ_w= 60%, pH = 7.4), accompanied by an intense green fluorescence turn-off behavior under UV_365nmillumination. The binding stochiometry between the ligand and Co²⁺was found to be 2:1, and the detection limit (DL) was calculated to be 0.41 × 10^-8M. In addition, it could be applied to detect Co²⁺in real water samples and on silica gel testing strip.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40477947","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}

{"title":"A novel conjugated polymer fluorescence probe for the detection of copper ions in aqueous media.","authors":"Lindan Gong,&nbsp;Lixiao Zhang,&nbsp;Rui Shen,&nbsp;Lin Zhang,&nbsp;Hengyuan Wang,&nbsp;Lu-An Fan","doi":"10.1088/2050-6120/ac9fa6","DOIUrl":"https://doi.org/10.1088/2050-6120/ac9fa6","url":null,"abstract":"<p><p>A novel ionic conjugated polymer fluorescent probe (<b>IP</b>) containing fluorenyls and imines was synthesized through a simple condensation method for the rapid detection of Cu²⁺. The probe exhibited a selective quenching response toward Cu²⁺over other common metal ions in phosphate-buffered saline (PBS) at a pH of 7. Moreover, the fluorescence intensity of<b>IP</b>was linearly proportional to the concentration of Cu²⁺when it ranged from 1 to 10<i>μ</i>M, and the limit of detection for Cu²⁺was 0.45<i>μ</i>M. Furthermore, the quenched fluorescence of<b>IP</b>by Cu²⁺was recovered after adding amino acids or ethylenediaminetetraacetic acid (EDTA), indicating that the probe could be recycled and is promising to reduce the detection cost of Cu²⁺in real samples.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40676335","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}

{"title":"Comparative study of upconversion and photoacoustic measurements of Er³⁺/Yb³⁺doped La₂O₃phosphor under 980 nm.","authors":"Minarul I Sarkar,&nbsp;Neeraj Kumar Mishra,&nbsp;Kaushal Kumar","doi":"10.1088/2050-6120/ac9fa7","DOIUrl":"https://doi.org/10.1088/2050-6120/ac9fa7","url":null,"abstract":"<p><p>The Er³⁺/Yb³⁺doped La₂O₃phosphor samples were synthesized by the combustion method and then photoluminescence and photoacoustic spectroscopic studies were done. Prepared samples were annealed at 800 °C, 1000 °C and 1300 °C and all samples were found in pure hexagonal phase as confirmed by XRD analysis. From FE-SEM images it is found that particle size increases with increase in annealing temperature. The frequency upconversion emission spectra of samples were recorded by exciting the sample with 980 nm diode laser and maximum emission intensity is obtained for the sample annealed at 1000 °C for 2 h. A photoacoustic cell was designed and wavelength dependent photoacoustic spectra were measured. The effect of sample storage time on radiative and non-radiative emission properties of sample was checked by measuring upconversion emission and photoacoustic spectra, simultaneously. It is observed that the emission intensity and photoacoustic signal both decreases with time. The maximum photoacoustic signal is obtained around 974 nm wavelength and it indicates its potential for photo-thermal therapy using infrared excitation.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40686724","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}