Methods and Applications in Fluorescence最新文献

{"title":"Fluorescence quenching determination of tetracyclines based on the synergistic oxidation effect between Fe₃O₄nanoparticles and tetracyclines.","authors":"Shiqi Guo,&nbsp;Yilin Chai,&nbsp;Yongjun Wu,&nbsp;Hongchao Guo,&nbsp;Fei Yu,&nbsp;Li-E Liu,&nbsp;Leiliang He,&nbsp;Songcheng Yu,&nbsp;Yongmei Tian,&nbsp;Jia Wang,&nbsp;Ruiying Yang,&nbsp;Ningge Jian,&nbsp;Yilin Wang","doi":"10.1088/2050-6120/acca61","DOIUrl":"https://doi.org/10.1088/2050-6120/acca61","url":null,"abstract":"<p><p>In recent years, tetracyclines (TCs) is a hot research topic. Herein, we report an interesting discovery using the complexation of oxytetracycline and metal ions. In this study, according to the properties of Fe₃O₄nanoparticles (Fe₃O₄NPs) as a nanoenzyme, it can be used to catalyze the oxidation of KI by H₂O₂to produceI3-,while at the same timeI3-binds to rhodamine 6G (Rh6G) to form a conjoined particle (Rh6G ∼ I₃)_n, leading to a decrease in the fluorescence intensity of Rh6G. However, in the presence of TCs, Fe₃O₄NPs have a synergistic effect with TCs, leading to enhanced catalytic activity, as well as better selectivity compared to the activity of other reducing enzymes. Consequently,the fluorescent signal based on a resonance scattering effect between Rh6G andI3-is dependent on the concentration of TCs, thus achieving highly facile and robust detection of TCs. The limits of detection (LOD) of the method were 20 nM, 10 nM and 40 nM for oxytetracycline(OTC), tetracycline(TC) and chlortetracycline(CTC), respectively. Most importantly, the method can be successfully applied to the detection of TCs in milk, eggs, and honey. The recoveries of spiked samples ranged from 83.11 to 118.95%. Thus, a stable, hands-on strategy for the detection of TCs is proposed, which has potential applications in the field of food safety and environmental protection.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 3","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9316156","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":"Room Temperature Phosphorescence of 5,6-Benzoquinoline.","authors":"Jose Chavez,&nbsp;Luca Ceresa,&nbsp;Emma Kitchner,&nbsp;Danh Pham,&nbsp;Zygmunt Gryczynski,&nbsp;Ignacy Gryczynski","doi":"10.1088/2050-6120/acc716","DOIUrl":"https://doi.org/10.1088/2050-6120/acc716","url":null,"abstract":"<p><p>Phosphorescence emission of 5,6-Benzoquinoline embedded in poly (vinyl alcohol) film has been studied at room temperature. A strong green long-lived emission was observed in films doped with 5,6-Benzoquinoline while illuminated on a UV plate. A broad phosphorescence emission spectrum is centered at about 500 nm. The phosphorescence excitation spectrum follows the absorption spectrum of 5,6-Benzoquinoline, except for a long-wavelength part, which is well beyond the absorption band. This long-wavelength part of the absorption spectrum is responsible for the forbidden S₀-T₁transition. The excitation at 430 nm resulted in the long-lived emission with a spectrum similar to the phosphorescence spectrum obtained with UV excitation within the absorption of 5,6-Benzoquinoline. The phosphorescence anisotropy obtained with a direct S₀-T₁excitation is positive, while the UV excitation is negative. In contrast to fluorescence, the phosphorescence intensity strongly depends on temperature. Phosphorescence lifetimes with UV and long-wavelength excitation are similar, with a mean value of about 0.5 s.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 2","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9587122","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":"Fluorescent carbon dots tailored iron oxide nano hybrid system for<i>in vivo</i>optical imaging of liver fibrosis.","authors":"Shaiju S Nazeer,&nbsp;Ariya Saraswathy,&nbsp;Nirmala Nimi,&nbsp;Elangovan Sarathkumar,&nbsp;A N Resmi,&nbsp;Sachin J Shenoy,&nbsp;Ramapurath S Jayasree","doi":"10.1088/2050-6120/acc009","DOIUrl":"https://doi.org/10.1088/2050-6120/acc009","url":null,"abstract":"<p><p>Hybrid nanoparticles are innovative invention of last decade designed to overcome limitations of single-component nanoparticles by introducing multiple functionalities through combining two or more different nanoparticles. In this study, we are reporting development of magneto-fluorescent hybrid nanoparticles by combining iron oxide and carbon nanoparticles to enable<i>in vivo</i>fluorescence imaging which also has all the required characteristic properties to use as Magnetic Resonance Imaging (MRI) contrast agent. In order to achieve dual-functional imaging, alginate and pullulan coated super paramagnetic iron oxide nanoparticles (ASPION and PSPION) and Carbon dots (Cdts) were synthesised separately. ASPIONs and PSPIONs were further chemically conjugated with Cdts and developed dual-functional nanohybrid particles ASPION-Cdts and PSPION-Cdts. Subsequently, evaluation of the materials for its size, functionalisation efficiency, fluorescence and magnetic properties, biocompatibility and cellular uptake efficiency has been carried out. Fluorescence imaging of liver fibrosis was performed<i>in vivo</i>in rodent model of liver fibrosis using the two nanohybrids, which is further confirmed by high fluorescence signal from the harvested liver.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 2","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10311824","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":"Compact and robust deep learning architecture for fluorescence lifetime imaging and FPGA implementation.","authors":"Zhenya Zang,&nbsp;Dong Xiao,&nbsp;Quan Wang,&nbsp;Ziao Jiao,&nbsp;Yu Chen,&nbsp;David Day-Uei Li","doi":"10.1088/2050-6120/acc0d9","DOIUrl":"https://doi.org/10.1088/2050-6120/acc0d9","url":null,"abstract":"<p><p>This paper reports a bespoke adder-based deep learning network for time-domain fluorescence lifetime imaging (FLIM). By leveraging thel1-norm extraction method, we propose a 1D Fluorescence Lifetime AdderNet (FLAN) without multiplication-based convolutions to reduce the computational complexity. Further, we compressed fluorescence decays in temporal dimension using a log-scale merging technique to discard redundant temporal information derived as log-scaling FLAN (FLAN+LS). FLAN+LS achieves 0.11 and 0.23 compression ratios compared with FLAN and a conventional 1D convolutional neural network (1D CNN) while maintaining high accuracy in retrieving lifetimes. We extensively evaluated FLAN and FLAN+LS using synthetic and real data. A traditional fitting method and other non-fitting, high-accuracy algorithms were compared with our networks for synthetic data. Our networks attained a minor reconstruction error in different photon-count scenarios. For real data, we used fluorescent beads' data acquired by a confocal microscope to validate the effectiveness of real fluorophores, and our networks can differentiate beads with different lifetimes. Additionally, we implemented the network architecture on a field-programmable gate array (FPGA) with a post-quantization technique to shorten the bit-width, thereby improving computing efficiency. FLAN+LS on hardware achieves the highest computing efficiency compared to 1D CNN and FLAN. We also discussed the applicability of our network and hardware architecture for other time-resolved biomedical applications using photon-efficient, time-resolved sensors.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 2","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9139171","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":"Multi-stimuli-responsive and dynamic color tunable security ink for multilevel anticounterfeiting.","authors":"Charu Dubey,&nbsp;Anjana Yadav,&nbsp;Diksha Baloni,&nbsp;Sachin Singh,&nbsp;Anjani Kumar Singh,&nbsp;Sunil Kumar Singh,&nbsp;Akhilesh Kumar Singh","doi":"10.1088/2050-6120/acbe92","DOIUrl":"https://doi.org/10.1088/2050-6120/acbe92","url":null,"abstract":"<p><p>Luminescent security features have been used for anticounterfeiting for a long time. However, constant effort is required to strengthen these security features to be ahead of counterfeiters. Here, we developed a multi-stimuli-responsive luminescent security ink containing Tb(ASA)₃Phen, K₂SiF₆:Mn^4+,and NaYF₄:Yb³⁺/Er³⁺luminescent materials in PVC gold medium. Tb(ASA)₃Phen complex shows a broad excitation band in the UV region; upon UV light radiation it shows strong greenish emission of Tb³⁺ions through the antenna effect. K₂SiF₆:Mn⁴⁺, on the other hand, has three excitation bands with maxima at 248, 354, and 454 nm which emit red light after excitation through these bands. NaYF₄:Yb³⁺/Er³⁺is used as an upconverting nanophosphor showing green emission under 976 nm laser excitation. Thus, the multi-stimuli-responsive luminescent security ink shows greenish, red, and green emissions under 367 nm, 450 nm, and 976 nm excitations, respectively. Furthermore, the distinct lifetimes of the activators in Tb(ASA)₃Phen and K₂SiF₆:Mn⁴⁺, i.e. 0.1708 ms and 8.165 ms, respectively, under 380 nm excitation make this ink suitable for dynamic anticounterfeiting as well. The ink shows a change in the emission color with time delay, after the removal of the 380 nm excitation source, from greenish yellow (at 0 delays) to reddish color after a delay of 7.5 ms. These unique optical features along with excellent photo-, chemical- and environmental stability make this ink useful for advanced-level anticounterfeiting.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 2","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9118341","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":"Tutorial: multiphoton microscopy to advance neuroscience research.","authors":"Iván Coto Hernández,&nbsp;Jenny Yau,&nbsp;Lars Rishøj,&nbsp;Nanke Cui,&nbsp;Steven Minderler,&nbsp;Nate Jowett","doi":"10.1088/2050-6120/acba66","DOIUrl":"https://doi.org/10.1088/2050-6120/acba66","url":null,"abstract":"<p><p>Multiphoton microscopy (MPM) employs ultrafast infrared lasers for high-resolution deep three-dimensional imaging of live biological samples. The goal of this tutorial is to provide a practical guide to MPM imaging for novice microscopy developers and life-science users. Principles of MPM, microscope setup, and labeling strategies are discussed. Use of MPM to achieve unprecedented imaging depth of whole mounted explants and intravital imaging via implantable glass windows of the mammalian nervous system is demonstrated.</p>","PeriodicalId":18596,"journal":{"name":"Methods and Applications in Fluorescence","volume":"11 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10752558","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":"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}