Fluorescence Of Fluorophore Research Articles

Exciton Dissociation and Recombination Afford Narrowband Organic Afterglow Through Efficient FRET.

Organic afterglow with long-persistent luminescence (LPL) after photoexcitation is highly attractive, but the realization of narrowband afterglow with small full-width at half-maximum (FWHM) is a huge challenge since it is intrinsically contradictory to the triplet- and solid-state emission nature of organic afterglow. Here, narrow-band, long-lived, and full-color organic LPL is realized by isolating multi-resonant thermally activated delayed fluorescent (MR-TADF) fluorophores in a glassy steroid-type host through a facile melt-cooling treatment. Such prepared host becomes capable of exciton dissociation and recombination (EDR) upon photoirradiation for both long-lived fluorescence and phosphorescence; and, the efficient Förster resonance energy transfer (FRET) from the host to various MR-TADF emitters leads to high-performance LPL, exhibiting small FWHM of 33nm, long persistent time over 10s, and facile color-tuning in a wide range from deep-blue to orange (414-600nm). Moreover, with the extraordinary narrowband LPL and easy processability of the material, centimeter-scale flexible optical waveguide fibers and integrated FWHM/color/lifetime-resolved multilevel encryption/decryption devices have been designed and fabricated. This novel EDR and singlet/triplet-to-singlet FRET strategy to achieve excellent LPL performances illustrates a promising way for constructing flexible organic afterglow with easy preparation methods, shedding valuable scientific insights into the design of narrow-band emission in organic afterglow.

Abstract 84: StarBright Dyes: Fluorophores with superior performance for multiplexing in flow cytometry and Western blotting

Abstract New StarBrightTM Dyes from Bio-Rad are bright fluorescent fluorophores ideal for many antibody-based applications, for example, western blotting and flow cytometry. Traditional fluorophores can be dim, have high cross laser excitation, or don’t work with all protocols, leading to poor data. StarBright Dyes have been designed to address these pain points. Western blotting secondary antibodies are available conjugated to StarBright Blue 700 and StarBright Blue 520 Dyes. Their brightness, the short exposure time required, and low background make them ideal for detection of a single target, or as shown here for multiplex detection of several proteins in combination with other common fluorophores. For flow cytometry, we have a full range of 32 StarBright Dyes excited by the most common laser lines: 355 nm, 405 nm, 488 nm, 561 nm, or 640 nm. They are available conjugated to highly cited clones against common immunophenotyping targets. Data shown here on the ZE5 Cell Analyser demonstrates how the features of StarBright Dyes can improve multiplexing immunophenotyping data. They have narrow excitation and emission spectral profiles, which reduce compensation and spread. This, combined with their exceptional brightness, enables high resolution of cell populations. They work in all buffers and fixatives, so including them in existing panels does not require a change in protocol. They can also be premixed in a master mix for over six months with no loss in performance. Premixes are ideal when using the same panel over an extended period, such as in clinical and longitudinal studies, to ensure reproducible results, also saving time and money. StarBright Dyes are ideal for multiplexing assays in both western blotting and flow cytometry. BIO-RAD and STARBRIGHT are trademarks of Bio-Rad Laboratories, Inc. in certain jurisdictions. All trademarks used herein are the property of their respective owner. Citation Format: Sharon Sanderson, Oliver Rosenwasser, Michael Blundell. StarBright Dyes: Fluorophores with superior performance for multiplexing in flow cytometry and Western blotting [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 84.

Comparative Analysis of Fluorescent Labeling Techniques for Tracking Canine Amniotic Stem Cells.

The utmost aim of regenerative medicine is to promote the regeneration of injured tissues using stem cells. Amniotic mesenchymal stem cells (AmMSCs) have been used in several studies mainly because of their easy isolation from amniotic tissue postpartum and immunomodulatory and angiogenic properties and the low level of rejection. These cells share characteristics of both embryonic/fetal and adult stem cells and are particularly advantageous because they do not trigger tumorigenic activity when injected into immunocompromised animals. The large-scale use of AmMSCs for cellular therapies would greatly benefit from fluorescence labeling studies to validate their tracking in future therapies. This study evaluated the fluorophore positivity, fluorescence intensity, and longevity of canine AmMSCs. For this purpose, canine AmMSCs from the GDTI/USP biobank were submitted to three labeling conditions, two commercial fluorophores [CellTrace CFSE Cell Proliferation kit - CTrace, and CellTracker Green CMFDA - CTracker (CellTracker Green CMFDA, CT, #C2925, Molecular Probes®; Life Technologies)] and green fluorescent protein (GFP) expression after lentiviral transduction, to select the most suitable tracer in terms of adequate persistence and easy handling and analysis that could be used in studies of domestic animals. Fluorescence was detected in all groups; however, the patterns were different. Specifically, CTrace and CTracker fluorescence was detected 6 h after labeling, while GFP was visualized no earlier than 48 h after transduction. Flow cytometry analysis revealed more than 70% of positive cells on day 7 in the CTrace and CTracker groups, while fluorescence decreased significantly to 10% or less on day 20. Variations between repetitions were observed in the GFP group under the present conditions. Our results showed earlier fluorescence detection and more uniform results across repetitions for the commercial fluorophores. In contrast, fluorescence persisted for more extended periods in the GFP group. These results indicate a promising direction for assessing the roles of canine AmMSCs in regenerative medicine without genomic integration.

Developing a Two-Photon "AND" Logic Probe and Its Application in Alzheimer's Disease Differentiation.

In Alzheimer's disease, hypochlorous acid involved in the clearance of invading bacteria or pathogens and butyrylcholinesterase engaged in the hydrolysis of the neurotransmitter acetylcholine are relatively significantly altered. However, there are few dual detection probes for hypochlorous acid and butyrylcholinesterase. In addition, single-response probes suffer from serious off-target effects and near-infrared probes do not easily penetrate the blood-brain barrier due to their excessive molecular weight. In this work, we constructed a two-photon fluorescent probe that recognizes hypochlorous acid and butyrylcholinesterase based on a dual-lock strategy. The thiocarbonyl group is oxidized in the presence of hypochlorous acid, and the hydrolysis occurs at the 7-position ester bond in the existence of butyrylcholinesterase, releasing a strongly fluorescent fluorophore, 4-methylumbelliferone. Excellent imaging was performed in PC12 cells using this probe, and deep two-photon imaging was observed in the brains of AD mice after tail vein injection with this probe. It indicates that the probe can provide a promising tool for the more precise diagnosis of Alzheimer's disease.

Study of relations between chemical, colour and fluorescence properties of raw and dried meat powders of cow and yak (Bos grunniens)

Gluteus medius, Longissimus thoracis, and Semitendinosus muscles from the cow and yak (Bos grunniens) reared in the Kyrgyz Republic were dried by convective (hot air) drying and freeze drying. The dried muscles were grinded into fine powders and along with raw muscles were evaluated for water activity (aW), chemical composition (moisture, fat, protein), colour characteristics (L, a, and b values), fluorescence of intrinsic fluorophores (tryptophan, vitamin A, and riboflavin). Processing of measured data tables using common components and specific weights analysis (CCSWA) showed close relations among the chemical, colour, and fluorescence data. CCSWA discriminated muscles depending on chemical composition, animal type, and drying technique applied based on the chemical properties, colour characteristics, and fluorescence spectra. The freeze drying was approved as a preferable dehydration technique comparing with convective drying as the one causing less discoloration to meat. Partial Least Squares Regression (PLSR) models developed using fluorescence spectra allowed accurate quantitative predicting of water activity (aW), moisture, fat, and protein contents, and colour characteristics (L, a, and b values).

Fluorescent homooxacalixarenes: recent applications in supramolecular systems.

This review covers recent advances (from 2006 to date) in supramolecular systems based on fluorescent homooxacalixarenes, namely hexahomotrioxacalix[3]arenes, dihomooxacalix[4]arenes and tetrahomodioxacalix[4]arenes, focusing on fluorescence sensing using their intrinsic fluorescence (built-in mesitol-like groups) or the extrinsic fluorescence of organic fluorophores, either covalently linked to the calixarenes or forming supramolecular complexes with them. Sensing applications of ions, ion pairs and neutral molecules are discussed, as well as the potential measurement of temperature based on thermally activated delayed fluorescence.

Rapid identification of bacteria by the pattern of redox reactions rate using 2′,7′-dichlorodihydrofluorescein diacetate

Bacterial infection is a life-threatening situation, and its rapid diagnosis is essential for treatment. Apart from medical applications, rapid identification of bacteria is vital in the food industry or the public health system. There are various bacterial identification techniques, including molecular-based methods, immunological approaches, and biosensor-based procedures. The most commonly used methods are culture-based methods, which are time-consuming. The objective of this study is to find a fingerprint of bacteria to identify them.Three strains of bacteria were selected, and seven different concentrations of each bacterium were prepared. The bacteria were then treated with two different molar concentrations of the fluorescent fluorophore, dichlorodihydrofluorescein diacetate for 30 minutes. Then, using the fluorescence mode of a multimode reader, the fluorescence emission of each bacterium is scanned twice during 60 minutes. Plotting the difference between two scans versus the bacteria concentration results in a unique fluorescence pattern for each bacterium.Observation of the redox state of bacteria, during 90 minutes, results in a fluorescence pattern that is clearly a fingerprint of different bacteria. This pattern is independent of fluorophore concentration. Mean Squares Errors (MSE) between the fluorescence patterns of similar bacteria is less than that of different bacteria, which shows the method can properly identify the bacteria.In this study, a new label-free method is developed to detect and identify different species of bacteria by measuring the redox activity and using the fluorescence fluorophore, dichlorodihydrofluorescein diacetate. This robust and low-cost method can properly identify the bacteria, uses only one excitation and emission wavelength, and can be simply implemented with current multimode plate readers.

Detection of long mRNA sequences by a Y-shaped DNA probe with three target-binding segments

Tumor-related mRNA detection is significant and interesting. The current mRNA detection method has the challenge of quantifying long mRNA sequences. Herein, a Y-shaped DNA probe with three target-binding segments was developed to detect tumor-related mRNA. This Y-shaped DNA probe (Y-probe) was assembled by six single DNA strands. Among these DNA strands, two DNA strands contained the split G-quadruplex sequence, and two DNA strands were modified with a pair of fluorophore and quencher, which were used to produce the detectable signal. In the presence of a long target mRNA sequence, target mRNA was hybridized with the three target-binding segments of the Y-probe, resulting in the increased fluorescence of G-quadruplex specific dye Thioflavin T and the decreased fluorescence of fluorophore, which could achieve the ratio detection of target mRNA. The Y-probe exhibited a low detection limit of 17.53 nM. Moreover, this probe showed high accuracy due to the benefits of three target-binding segments.

A terpyridyl-rhodamine hybrid fluorescent probe for discriminative sensing of Hg (II) and Cu (II) in water and applications for molecular logic gate and cell imaging

Sensitive and discriminative sensing of more than one analyte with a single fluorescent probe is significant and challenging. Herein a new terpyridyl-rhodamine hybrid, namely TRH, has been rationally designed and prepared with two responsive groups in the molecular structure, which facilitate the discriminative detection of Hg2+ and Cu2+ ions in water with detection limits of 4.9 and 53.3 nM by ratiometric fluorescence change (F595/F485) and fluorescence quenching, respectively. Investigations show that the selectivity to Hg2+ ions can be attributed to Hg2+-promoted spirolactam ring opening and further hydrolysis, followed by a through-bond energy transfer (TBET) process. The selective fluorescence quenching to Cu2+ ions probably can be ascribed to the binding Cu2+ to terpyridyl that triggers a ligand-to-metal charge transfer (LMCT) process, which can also efficiently inhibit the TBET process induced by Hg2+ ions and promotes the discriminative sensing of Cu (II) and Hg (II). In addition, the fluorescent responses to Hg2+ and Cu2+ ions cover a wide pH range. Moreover, a combinatorial logic gate with the functions of NOR and INHIBIT has been fabricated by using Hg2+ and Cu2+ ions as chemical input signals, and fluorescence at 485 and 595 nm as output signals. Besides, TRH also exhibits sensitive and discriminative sensing ability to Hg2+ and Cu2+ ions by the fluorescence of rhodamine fluorophore. Significantly, based on the fluorescence signal output of rhodamine moiety, TRH can be used as a tracer for the discriminative sensing of Hg2+ and Cu2+ ions by using living cells.

Effects of Cascading Optical Processes: Part III. Impacts on Spectroscopic Measurements of Fluorescent Samples.

Cascading optical processes involve sequential photon-matter interactions triggered by the same individual excitation photons. Parts I and II of this series explored cascading optical processes in scattering-only solutions (Part I) and solutions with light scatterers and absorbers but no emitters (Part II). The current work (Part III) focuses on the effects of cascading optical processes on spectroscopic measurements of fluorescent samples. Four types of samples were examined: (1) eosin Y (EOY), an absorber and emitter; (2) EOY mixed with plain polystyrene nanoparticles (PSNPs), which are pure scatterers; (3) EOY mixed with dyed PSNPs, which scatter and absorb light but do not emit; and (4) fluorescent PSNPs that are simultaneous light absorbers, scatterers, and emitters. Interference from both forward scattered and emitted photons can cause nonlinearity and spectral distortion in UV-vis extinction measurements. Sample absorption by nonfluorogenic chromophores reduces fluorescence intensity, while the effect of scattering on fluorophore fluorescence is complicated by several competing factors. A revised first-principles model is developed for correlating the experimental fluorescence intensity with the sample absorbance in solutions containing both scatterers and absorbers. The optical properties of fluorescent PSNPs of three different sizes were systematically investigated by using integrating-sphere-assisted resonance synchronous spectroscopy, linearly polarized resonance synchronous spectroscopy, UV-vis, and fluorescence spectroscopy. The insights and methodology provided in this work should help improve the reliability of spectroscopic analyses of fluorescent samples, where the interplay among light absorption, scattering, and emission can be complex.

PET/d-PET (PdP) Pairing for the Design of Dual-Channel Probes.

Design principles of two-channel fluorescence probes are limited. Herein, we report a new principle, i.e., PET/d-PET (PdP) pairing, for the rational design of two-channel probes. Two fluorophores are required in such a PdP-type probe. They mutually quench their fluorescence via PET and d-PET. In the presence of an analyte-of-interest, such a PdP pair is converted into a FRET pair for signaling. The embodiment of such a principle is Rh-TROX, by tethering a rhodamine fluorophore with an ROS-sensitive probe (TotalROX). Fluorescence of both fluorophores in Rh-TROX was quenched as expected. The addition of highly reactive oxidative species led to the recovery of the fluorescence properties of both. The simultaneous fluorescence enhancement in two channels is a viable way to avoid false-positive signals. The new PdP principle could potentially be applied to the development of probes for another range of substrates.

Fluorescent assay for alkaline phosphatase by integrating strand displacement amplification with DNAzyme-catalytic recycling cleavage of molecular beacons

A fluorescence sensing method for the quantification of alkaline phosphatase (ALP) was developed by integrating the strand displacement amplification with DNAzyme-catalytic recycling cleavage of molecular beacons. ALP can hydrolyze a 3′-phosphoralated primer into a 3′-hydroxy primer which can initiate the strand displacement amplification to produce the Mg2+-dependent DNAzyme. The DNAzyme can then catalyze the cleavage of the DNA molecular beacon labeled with FAM fluorophore at its 5′-end and BHQ1 quencher at its 3′-end, turning on the fluorescence of FAM fluorophore. The content of ALP in a sample can be deduced from the measured fluorescence intensity. Due to the cascading nature of its amplification strategy, the proposed method achieved sensitive and specific ALP detection in human serum samples. Its results were in good consistent with the corresponding values obtained by a commercial ALP detection kit. The limit of detection of the proposed method for ALP is about 0.015 U/L, lower than some methods recently reported in literature, demonstrating its potential for ALP detection in biomedical research and clinical diagnosis.

An off-on quinoxaline-based fluorescent probe for lighting up biothiols in living cells and zebrafish

A novel fused four-ring quinoxaline fluorophore and a maleimide receptor were firstly integrated into one molecule to develop a novel, sensitive and highly effective probe for biothiols detection. The fluorescence of quinoxaline fluorophore was quenched by the maleimide group via the photoinduced electron transfer (PET) mechanism. After the Michael addition of the biothiols towards maleimide, the PET process was blocked and the fluorescence restored. The above sensing mechanisms were confirmed by the mass spectroscopy and explained by density functional theory (DFT) calculations, ensuring QX9M as a highly selective probe towards biothiols over other amino acids. Moreover, the probe featured a good linearity range and a low detection limit to Cys, Hcy and GSH. For the practical applications, the probe can be used to monitor the biothiols not only in living cells but also in zebrafish with an off-on process.

A naphthalimide functionalized fluoran with AIE effect for ratiometric sensing Hg2+ and cell imaging application

The pollution caused by mercury ions (Hg2+) poses a potential threat to public health. Therefore, monitoring Hg2+ concentration in the environment is necessary and significant. In this work, a naphthalimide functionalized fluoran dye NAF has been prepared, which shows a new red-shift in emission at 550 nm with the maximum intensity in a mixture of water-CH3CN (v/v = 7/3) due to aggregating induced emission (AIE) effect. Meanwhile, NAF can be employed as a Hg2+ ions sensor, which displays a selective and sensitive response to Hg2+ ions by the reduced fluorescence of naphthalimide fluorophore and increased fluorescence of fluoran group, respectively, showing ratiometric fluorescence signal changes with more than 65-fold emission intensity ratio increase and naked eyes visible color change. In addition, the response time is fast (within 1 min) and the sensing can be conducted in a wide pH range (4.0–9.0). Moreover, the detection limit has been evaluated to be 5.5 nM. The sensing mechanism may be attributed to the formation of a π-extended conjugated system due to the Hg2+ ions-induced conversion of spironolactone to the ring-opened form, partially accompanied by the fluorescence resonance energy transfer (FRET) process. Significantly, NAF exhibits suitable cytotoxicity to living HeLa cells, which allows it to be utilized for ratiometric imaging of Hg2+ ions assisted by confocal fluorescence imaging.

Significant Improvement of Solid‐State One‐/Two‐Photon Excited Luminescence in HOFs via Constructing Hydrogen‐Bonded Solvate Model

AbstractA hydrogen‐bonded solvate (HBS) model is herein proposed to construct hydrogen‐bonded organic frameworks (HOFs), for enhancing the solid‐state one‐/two‐photon excited fluorescence (1/2PEF) of organic fluorophores. Two photonic HOFs (ZJU‐HOF‐25 and ZJU‐HOF‐26) are synthesized by using the same organic fluorophore and the fluorophore in them features similar arrangement. The most obvious structural distinction between the two HOFs is the existence of solvent molecules in the crystal cell of ZJU‐HOF‐25. ZJU‐HOF‐25 is regarded as an ideal HBS material where solvent molecules separate fluorophores apart just like dissolving them. But ZJU‐HOF‐26 contains no solvent molecules and the fluorophores are connected directly via hydrogen bonds among them. A significant quantum yield (η) increase is realized from amorphous fluorophores (η ≈0%) to HBS‐based ZJU‐HOF‐25 (η ≈21.75%), while ZJU‐HOF‐26 displays poor 1PEF (η ≈0%). ZJU‐HOF‐25 also exhibits much stronger 2PEF with the two‐photon action cross section larger than ZJU‐HOF‐26 by almost two orders of magnitude. These phenomena are mainly attributed to that the solvent molecules in ZJU‐HOF‐25 benefit the homogeneous separation and conformation fixation of fluorophores, suppressing the non‐radiative transition. The HBS model thus shows the fantastic validity to improve solid‐state optical properties of organic materials, providing guidance for exploring advanced optical materials.

A Novel Method for Measuring Mitochondrial Respiratory Parameters in Wheat Paleae (Paleae Superior) Using the XF24 Analyzer.

Understanding the influence of secondary metabolites from fungi on the mitochondria of the host plant during infection is of great importance for the knowledge of fungus-plant interactions in general; it could help generate resistant plants in the future and in the development of specifically acting plant protection products. For this purpose, it must first be possible to record the mitochondrial parameters in the host plant. As of the date of this protocol, no measurements of mitochondrial respiration parameters have been performed in wheat paleae. The protocol shown here describes the measurements using the XF24 analyzer, which measures the rate of oxygen consumption in the sample by changes in the fluorescence of solid-state fluorophores. This procedure covers the preparation of samples for the XF24 analyzer and the measurement of mitochondrial parameters by adding specific mitochondrial inhibitors. It also shows the necessary approach and steps to be followed to obtain reliable, reproducible results. This is a robust protocol that allows the analysis of mitochondrial respiration directly in the wheat paleae. It demonstrates an important add-on method to existing screenings and also offers the possibility to test the effects of early infection of plants by harmful fungi (e.g., Fusarium graminearum) on mitochondrial respiration parameters. Key features This protocol offers the possibility of testing the effects of early infection of plants by pathogens on mitochondrial respiration parameters. This protocol requires a Seahorse XF24 Flux Analyzer with Islet Capture Microplates and the Seahorse Capture Screen Insert Tool. Graphical overview.

Fluoranthene-based derivatives for multimodal anti-counterfeiting and detection of nitroaromatics

Two novel fluoranthene ensembles with ethyl alcohol (FOH) and ethanethiol (FSH) functionality with distinct diagonal and ladder arrangements in the crystal lattices were developed for Latent Fingerprints (LFPs) towards analysis of explosives.

A Rapid Protocol for Preparing 8-Aminopyrene-1,3,6-Trisulfonate-Labeled Glycans for Capillary Electrophoresis-Based Enzyme Assays.

Purified glycan standards are required for glycan arrays, characterizing substrate specificities of glycan-active enzymes, and to serve as retention-time or mobility standards for various separation techniques. This chapter describes a method for the rapid separation, and subsequent desalting, of glycans labeled with the highly fluorescent fluorophore 8-aminopyrene-1,3,6-trisulfonate (APTS). By using fluorophore-assisted carbohydrate electrophoresis (FACE) on polyacrylamide gels, a technique amenable to equipment readily available in most molecular biology laboratories, many APTS-labeled glycans can be simultaneously resolved. Excising specific gel bands containing the desired APTS-labeled glycans, followed by glycan elution from the gel by simple diffusion and subsequent solid-phase extraction (SPE)-based desalting, affords a single glycan species free of excess labeling reagents and buffer components. The described protocol also offers a simple, rapid method for the simultaneous removal of excess APTS and unlabeled glycan material from reaction mixtures. This chapter describes a FACE/SPE procedure ideal for preparing glycans for capillary electrophoresis (CE)-based enzyme assays, as well as for the purification of rare, commercially unavailable glycans from tissue culture samples.

Reconstruction of fluorophore absorption and fluorescence lifetime using early photon mesoscopic fluorescence molecular tomography: a phantom study.

Fluorescence molecular lifetime tomography (FMLT) plays an increasingly important role in experimental oncology. The article presents and experimentally verifies an original method of mesoscopic time domain FMLT, based on an asymptotic approximation to the fluorescence source function, which is valid for early arriving photons. The aim was to justify the efficiency of the method by experimental scanning and reconstruction of a phantom with a fluorophore. The experimental facility included the TCSPC system, the pulsed supercontinuum Fianium laser, and a three-channel fiber probe. Phantom scanning was done in mesoscopic regime for three-dimensional (3D) reflectance geometry. The sensitivity functions were simulated with a Monte Carlo method. A compressed-sensing-like reconstruction algorithm was used to solve the inverse problem for the fluorescence parameter distribution function, which included the fluorophore absorption coefficient and fluorescence lifetime distributions. The distributions were separated directly in the time domain with the QR-factorization least square method. 3D tomograms of fluorescence parameters were obtained and analyzed using two strategies for the formation of measurement data arrays and sensitivity matrices. An algorithm is developed for the flexible choice of optimal strategy in view of attaining better reconstruction quality. Variants on how to improve the method are proposed, specifically, through stepped extraction and further use of a posteriori information about the object. Even if measurement data are limited, the proposed method is capable of giving adequate reconstructions but their quality depends on available a priori (or a posteriori) information. Further research aims to improve the method by implementing the variants proposed.

Plasmonic Sensor and Surface Enhanced Fluorescence Imaging Based on Hollow Nanocone Arrays

Hollow nanocone arrays are fabricated by a low-cost and efficient colloidal lithography (CL) technique. The hollow nanocone arrays are then reversed to make only the tips contact the substrate. The optical properties of the obverse and inverse hollow nanocone arrays are determined by the surrounding environment, showing different reflection spectra and structure dependence. The inverse hollow nanocone arrays show a relative index sensitivity of 70% per RIU with strict linearity. The fluorescence of fluorophore or staining cells can be facilely enhanced by placing them on the tips of the hollow nanocone arrays, while having no quenching effect. The study of the obverse and inverse hollow nanocone arrays can benefit the understanding of the effect of the environment on the plasmonic resonances. The hollow nanocone arrays are promising to serve as high-performance plasmonic sensors and versatile substrates for surface-enhanced fluorescence imaging.