Fluorescent Powder Research Articles

Near-infrared nonlinear WLEDs with high stability through atomic-level regulation and photosensitive resin encapsulating by 3D printing

Upconversion luminescence (UCL) is a nonlinear opticalphenomenon where long wavelength radiation is converted to shorter wavelength via a two-photon or multi-photon mechanism. The construction of near-infrared nonlinear WLEDs can achieve effective utilization of sunlight. This work starts with "functional Motifs" and regulates the nonlinear luminescent materials at the molecular level by combining DFT calculations and high-throughput techniques. As expected, the optimized geometric structures, band structures, and density of states of Ba2YbF7:Ln3+ were successfully obtained by assembling [BaBr4] and [LnBr4] functional Motifs. Subsequently, Ba2YbF7:Ln3+ single phosphor was prepared and further encapsulated into resin to achieve highly stable upconversion white light using 3D printing technology. After being placed for 8 months, the luminescence intensity and spectral shape of the resin coated sample remain unchanged. The color coordinates of the WLED device constructed with Ba2YbF7:Tm3+/Er3+ single fluorescent powder is (0.3086, 0.3163) and the related color temperature (CCT) is 6863 K. The optimized material has a maximum color rendering index of 83. This work provides new insights and ideas for improving the luminescence stability of upconversion WLED using 3D printing technology.

Facile Synthesis of Fluorescent Carbon Quantum Dots with High Product Yield Using a Solid-Phase Strategy.

The liquid-phase method is the most commonly utilized strategy for synthesizing fluorescent carbon quantum dots (CQDs). However, the liquid-phase synthesis of CQDs faces challenges such as low yield, complex purification, and the use of toxic solvents, which limit large-scale production and practical applications. In this study, fluorescent CQDs with a high product yield of 78% were synthesized using glucose as a carbon source through a green and facile one-step solid-phase approach, without solvents or post-treatment. A systematic study of the structure and fluorescence properties of the synthesized CQDs was conducted using various characterization techniques. The results indicated that the mean size of obtained CQDs was 4.1 nm, and that their surface had abundant oxygen-containing functional groups, resulting in favorable water solubility. The synthesized CQDs exhibited excitation-dependent fluorescence, with optimal excitation and emission wavelengths at 358 and 455 nm, respectively. Additionally, the CQDs solution showed bright blue fluorescence under 365 nm UV light, with a quantum yield of 6.21% and a fluorescence lifetime of 3.02 ns. This study offers valuable insights into the green and efficient synthesis of fluorescent CQDs powder.

A novel highly thermally stable phosphor powder Ba2LuSbO6: Eu3+ for latent fingerprint visualization

In modern forensic science, fingerprints are critical evidence due to their uniqueness and difficulty to replicate. However, it is challenging to observe and identify some latent fingerprints (LFP), because alternative processing methods for recognition are often required. The use of Eu3+-doped phosphors, which emit red-orange light, presents an effective approach for enhancing the visibility of LFP. Eu3+-doped Ba2LuSbO6 (BLSO) phosphors were synthesized using a high-temperature solid-state method, aiming to improve the recognition of LFP for enhanced fingerprint identification. The phase structure of the fluorescent powder samples was analyzed through X-ray diffraction (XRD) combined with Rietveld refinement, as well as scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Photoluminescence spectra of Ba2LuSbO6: xEu3+ phosphor samples exhibit orange-red emission peaks at 595 and 618 nm when excited by 250 nm deep ultraviolet light. Concentration quenching is observed at a doping concentration of 20 mol%. The Ba2LuSbO6: 0.2Eu3+ phosphor sample demonstrates exceptional thermal stability, with value of 92.50% at 423 K. The quantum efficiency of the Ba2LuSbO6: 0.2Eu3+ phosphor sample was evaluated using an integrating sphere, yielding an IQE of 79.34%. In order to visualize latent fingerprints (LFPs), hydrophilic BLSO: 0.2Eu3+ phosphors were transformed into hydrophobic BLSO: 0.2Eu3+@OA phosphors through a coating of oleic acid (OA). The BLSO: 0.2Eu3+@OA phosphor proves capable of generating dependable LFP fluorescence images with superior contrast and resolution. These findings underscore the significant potential for application of BLSO: 0.2Eu3+ products LFP visualization.

Floral morphology is associated with pollen deposition patterns on moth bodies

AbstractFloral syndromes can be a useful tool for predicting the identity of pollinators from floral morphology. However, the reliability of floral syndromes are still debated in the literature, and can often result in effective pollinators being overlooked. Pollination by moths has historically been associated with a floral syndrome comprising white tubular flowers that are heavily scented at night, but there have been few experimental tests of this association. To test whether moths preferentially land on flowers that are white and tubular, we allowed two moth species (Agrotis ipsilon (Hufnaggel, 1766) and Ichneutica mutans (Walker, 1857)) to choose freely between three plant species (Vaccinium corymbosum, Ericaceae, Pittosporum tenuifolium, Pittosporaceae, and two forms of Leptospermum scoparium, Myrtaceae) which represent four different floral morphologies. Anthers on the flowers were marked with fluorescent powder dye (pollen‐tracker), with the presence of pollen‐tracker on moth bodies after the experiment indicating floral visitation. We detected no floral preferences for any of the plant species by either moth species, suggesting moths will visit flowers that lack features associated with the syndrome even when in the presence of white, tubular flowers which might be predicted to be more attractive to moths. We also examined moth bodies to determine where pollen‐tracker was carried most often and if this varied among the floral types. Our results indicate that some moth body parts may be more important than others for pollen transfer, depending on the morphology of the flowers visited. After visiting tubular flowers (Vaccinium and Pittosporum), pollen‐tracker was most often located on the proboscis, but after visiting open‐access flowers (Leptospermum) pollen‐tracker was most often located on the legs. Future studies looking at the presence of pollen on moth bodies should consider this and ensure the entire moth body is examined for the presence of pollen.

Dual-mode visual imaging of latent fingerprints based on organic fluorescent probe with enhanced TICT emission

Fluorescence-based imaging has emerged as a promising technique for high-resolution visualization of latent fingerprints (LFPs), but detecting LFPs by fluorescent probes remains challenging at present. Herein, a water-soluble fluorescent dye (DEPN) with red emission and twisted intramolecular charge transfer (TICT) properties was synthesized, which function as a dual-mode in-situ imaging probe for LFPs. The desired solid composite fluorescent fingerprint powder DEPN@MMT can be obtained by milling with montmorillonite (MMT) to realize the imaging of LFPs with 1–3 levels of details, which has the advantages of simple preparation, low doping ratio, good photostability, and is not limited by the substrate. Comparison with the actual fingerprint details extracted by fingerprint reader revealed a good match between the both, indicating that the fingerprint powder has high application value. The permanent preservation of LFPs with different curvatures was also realized by making rubbings. In addition, DEPN was able to image LFPs in aqueous solution with a concentration of 50 μM over a wide pH range, and it took only 20 s to obtain high-quality images that met the NFIQ2 detection standard. This dual-mode imaging probe of LFPs is highly practical, offering adaptable detection patterns for a range of complicated situations. It provides a valuable method for rapid and convenient visualization of LFPs, as well as their subsequent preservation and analysis.

UV Fluorescent Powders as a Tool for Plant Epidemiological Studies

UV Fluorescent Powders as a Tool for Plant Epidemiological Studies

Synergistic effect induces self crystallization of CsPbBr3 quantum dots in borosilicate glass matrix by LiF

Cesium lead halide perovskite (CsPbX3) quantum dots (QDs) are recognized as viable substitutes for conventional fluorescent powder color converters, which can improve the color gamut and reproducibility of liquid crystal displays (LCDs). Encapsulating QDs in glass can effectively solve the water oxygen stability of QDs, but the glass matrix impedes the nucleation of QDs and the precipitation of QDs requires secondary heating. In our research, we successfully accomplished the self-crystallization of CsPbBr3 QDs facilitated by LiF within a B2O3-SiO2-ZnO borosilicate glass matrix. The results indicate that the self crystallization of CsPbBr3 QDs induced by LiF in borosilicate glass matrix has a synergistic effect. The Li + ions can break the glass network structure and facilitate ionic migration and transport, while F− ions have good electronegativity due to ion aggregation, and can strongly attract Cs+ and Pb2+ ions with larger atomic radii, thereby promoting the rapid nucleation and growth of CsPbBr3 QDs, ultimately synthesizing QDs with uniform particle size, narrow half peak width, good optical properties, and thermal stability.

A Review of the Occurrence and Recovery of Rare Earth Elements from Electronic Waste.

Electronic waste (e-waste) contains valuable rare earth elements (REEs) essential for various high-tech applications, making their recovery crucial for sustainable resource management. This review provides an overview of the occurrence of REEs in e-waste and discusses both conventional and emerging green technologies for their recovery. Conventional methods include physical separation, hydrometallurgy, and pyrometallurgy, while innovative approaches such as bioleaching, supercritical fluid extraction, ionic liquid extraction, and lanmodulin-derived peptides offer improved environmental sustainability and efficiency. The article presents case studies on the extraction of REEs from waste permanent magnets and fluorescent powders, highlighting the specific processes involved. Future research should focus on developing eco-friendly leaching agents, separation materials, and process optimization to enhance the overall sustainability and efficiency of REE recovery from e-waste, addressing both resource recovery and environmental concerns effectively.

Identification of decedents by restoring mummified fingerprints: Forensic dermatology in the investigation of mummy dermatoglyphics

Fingerprints are created by elevations and depressions on the fingertip pads. Each person has their own unique fingerprints, which can be used in the identification of that individual when alive, during the immediate postmortem period, or even after the digits have become mummified. Mummification can occur naturally; it can be partial (such as localized to only the hands and feet), extensive, or complete. Obtaining fingerprints after the skin has become mummified can be attempted while the digits remain attached to the hand, but the digits may need to be removed from the hand, and the finger pads may also need to be separated from the underlying bone to secure an adequate fingerprint. The mummified tissue often needs to be rehydrated; numerous solutions have been used that increase the turgor of the digits, provide softening and pliability of the tissue, and enhance the details of the finger pad ridges. An aqueous solution of sodium carbonate (either combined with acetic acid or combined with 95% ethanol and distilled water) was found to be most effective for rehydration. Thereafter, various techniques can be attempted to obtain the fingerprint. These include the traditional method of inking and rolling of the finger or photographing the finger. Powders (such as aluminum powder, black fingerprint powder, white cornstarch-based powder, or fluorescent powder) can be used to enhance the ridge features; adhesive tape can be pressed against the powdered digit and the print pattern preserved by applying the adhesive tape to a clear transparency sheet. Molds (using modeling clay or silicone rubber) and casts (using plaster of paris, dental casting materials, or putty) of the digits can be created; either the molds or the casts or both can be photographed with or without prior application of fingerprint powder. Transillumination, using a fiber optic light source to illuminate the epidermis and underlying remaining dermis of a scraped and defleshed finger pad, can be used to demonstrate the finger ridge pattern when photographing the tip of the digit. Forensic dermatology can play an integral role in obtaining fingerprints from mummified digits, which can be successfully used for the identification of a decedent.

Strongly Fluorescent Blue-Emitting La2O3: Bi3+ Phosphor for Latent Fingerprint Detection.

Blue-emitting bismuth-doped lanthanum oxide (La2O3: Bi3+) with various concentrations of Bi was synthesized using the sol-gel combustion method and used for visualization of latent fingerprints (LFPs). An X-ray diffraction (XRD) study revealed the hexagonal structure of the phosphors and total incorporation of the bismuth in the La2O3 matrix. Field Emission Scanning Electron Microscopy (FE-SEM) and Fourier Transform Infrared Spectroscopy (FTIR) were used to study the morphology and the relative vibrations of the synthesized samples. Photoluminescence (PL) studies showed strong blue emission around 460 nm due to the 3P1 → 1S0 transition. Clear bright-blue fingerprint images were obtained with the powder dusting method on various surfaces like aluminum, compact discs, glass, wood and marble. A first evaluation of these images indicated a clear visualization of all three levels of details and a very high contrast ranging from 0.41 on marble to 0.90 on aluminum. As a further step, we used an algorithm for extracting fingerprint minutiae with which we succeeded in detecting all three levels of fingerprint details and even the most difficult ones, like open and closed pores. According to these analyses, La2O3: Bi phosphor is demonstrated to be an effective blue fluorescent powder for excellent visualization of latent fingerprints.

A Novel Synthesis Method of Dumbbell-like (Gd1-xTbx)2O(CO3)2·H2O Phosphor for Latent Fingerprint.

A novel method for synthesizing dumbbell-shaped (Gd1-xTbx)2O(CO3)2·H2O (GOC:xTb3+) phosphors using sodium carbonate was investigated. An amount of 1 mmol of stable fluorescent powder can be widely prepared using 3-11 mmol of Na2CO3 at a pH value of 8.5-10.5 in the reaction solution. The optimal reaction conditions for the phosphors were determined to be 7 mmol for the amount of sodium carbonate and a pH of 9.5 in the solution. Mapping analysis of the elements confirmed uniform distribution of Gd3+ and Tb3+ elements in GOC:xTb3+. The analysis of fluorescence intensity shows that an optimal excitation wavelength of 273 nm is observed when the concentration of Tb3+ is between 0.005 and 0.3. The highest emission intensity was observed for GOC:0.05Tb3+ with a 57.5% maximum quantum efficiency. The chromaticity coordinates show that the color of GOC:Tb3+ is stable and suitable for fluorescence recognition. Latent fingerprint visualization reveals distinctive features like whorls, hooks, and bifurcations. Therefore, the sodium carbonate method offers an effective alternative to traditional urea chemical reaction conditions for preparing GOC:Tb3+.

Microwave synthesis of composite of AgInS2 quantum dots and zeolitic imidazolate framework-8 for application in white light emitting diodes

Preparation of AgInS2 quantum dots (AIS QDs) with high photoluminescence quantum yield (PLQY) and thermal stability remains an important challenge. In this paper, AIS QDs were successfully introduced into zeolitic imidazolate framework-8 (ZIF-8) by microwave-assisted hydrothermal method. Due to the effective isolation of the ZIF-8, the AIS QDs avoid the concentration quenching when they were assembled into white light emitting diodes (WLEDs) devices as color conversion materials. More importantly, the generation of ZnS layer between the interfaces of AIS QDs and ZIF-8 can efficiently improve the optical performance of AIS QDs, resulting in the fluorescence lifetime extended to 470.05 ns. Meanwhile, the PLQY of AIS/ZIF-8 composite reached up 34.30 % when microwave hydrothermal heating at 120 °C for 60 min with AgIn/Zn=1/3, which was higher than that of the pristine AIS QDs as 25.30 %. Finally, the WLED devices were fabricated by combining AIS/ZIF-8 composite fluorescent powder with (Ba, Sr)Si2O2N2:Eu2+ phosphors and blue LED. At 20 mA, the AIS/ZIF-8 based WLED shows the luminous efficiency (LE) of 44.54 lm/W, correlated color temperature (CCT) of 4242 K and color rendering index (CRI) of 89.1. Moreover, the Commission International de L'Eclairage (CIE) was (0.36, 0.35), indicating the WLED emited warm white light. The present strategy aims at enhancing the optical performance of AIS QDs, which also may trigger the development of QDs-based WLED.

ProtectaBEE® and bee vectoring: innovating hive-based health with inspensing technology for sustainable apiculture

Apivectoring, or bee vectoring, employs managed bees to distribute powders containing disease and pest-fighting biocontrol agents during pollination flights to crops. Our research introduces a novel application of this concept, termed inspensing, which leverages bee vectoring for hive-based benefits. In inspensing, bees traverse through a carrier powder combined with products aimed at combating pathogens or pests within the hive. To facilitate this, we developed the ProtectaBEE® system, an innovative beehive-entrance technology that guides bees through a compartment inoculated with an inspensing powder. This system facilitates the application of beneficial agents into the hive without the need for beekeepers to open the hive, thereby streamlining the treatment process and reducing hive disturbance. To analyze the effectiveness of the system, we employed a fluorescent tracer in a powder formulation for tracking distribution throughout the hive. Complementing this, we inspensed a living dry powder-formulated biocontrol agent, Beauveria bassiana, an entomopathogenic fungus known to reduce Varroa mite populations, and detected its presence in the hive using PCR. The fluorescent powder was detected in 78.8% of the samples while B. bassiana was confirmed in up to 86.2% of larvae and 91.7% of mites. Our results underscore the system's efficacy in delivering material throughout the hive and affirm the potential for inspensing dry-powder-formulated biocontrol agents to manage Varroa destructor. Inspensing paves new paths for optimizing bee health and pest control strategies, streamlining disease management, simplifying hive maintenance, and minimizing beekeeper intervention, all contributing to sustainable apiculture.

Development of silica gel from Lapindo volcanic mud as fluorescent fingerprint powder based on methyl orange

Fingerprint powder remains one of the most effective techniques for identifying individuals from their latent fingerprints. Visualizing latent fingerprints requires powder with high color contrast and strong adhesive to be easily applied on various substrates. The utilization of silica gel extracted from local materials of Lapindo volcanic mud can be applied for fluorescent fingerprint powder based on methyl orange. The powder was synthesized by the sol-gel method, followed by the impregnation of methyl orange as a dye with varying loads. The powders exhibit an amorphous structure and nanoparticle size with an average particle diameter of 80.93 nm by spherical morphology interconnected to form agglomerations. The powder contains silanol, siloxane, azo, and carboxylate functional groups derived from its precursors. The dusting method proves the performance of fluorescent fingerprint powder on porous and non-porous substrates hereafter observed under white light and UV light. The powder containing 0.05 gs of methyl orange per gram of silica gel is the most effective in revealing fingerprint patterns on non-porous surfaces. It has mesoporous properties with a specific surface area of 7.95 m2g−1 and a pore diameter of 23.14 nm. SiMO retained its full capability after two years of storage, indicating it is a great choice for forensic investigations.

Preliminary investigations into the use of the ancient pigments Han blue and Han purple as luminescent dusting powders for the detection of latent fingermarks

Here we present our preliminary studies into the inorganic pigments Han blue (BaCuSi4O10) and Han purple (BaCuSi2O6) as near-infrared luminescent fingerprint dusting powders. These pigments were developed in ancient China around 800 BCE and both show luminescence in the NIR region. There remains, however, ambiguity in the literature concerning their photophysical properties. Samples of Han blue and Han purple artist’s pigments were characterized by optical microscopy, infrared, ultraviolet-visible absorbance and luminescence spectroscopy. Their performance as fingerprint dusting powders, without any further treatment, on non-porous surfaces were compared to exfoliated lipophilic coated Egyptian blue and commercial fluorescent powders in a pilot study. These results demonstrate for the first time that both ancient pigments show promise as alternative dusting powders for latent fingermarks.

A prime red phosphor Ca3Gd(AlO)3(BO3)4:Eu3+ with high color purity for low color temperature pc-WLEDs

A series of excellent thermal stability red phosphors Ca3Gd(AlO)3(BO3)4:Eu3+ were synthesized by conventional solid-state reaction method. Through the fluorescence spectrometer, the research results make clear that this phosphor has a best excitation wavelength of 396 nm, and 0.7 mol% of doping is optimal. The interaction between ions causes a concentration-quenching phenomenon when the doping concentration is too high. Under the excitation of 396 nm ultraviolet light, there is a significant emission peak at 623 nm due to the energy level transition of 5D0→7F2 in the outer layer of the fluorescent powder. The color purity of the Ca3Gd0.3(AlO)3(BO3)4:0.7Eu3+ is 98.8 %, which means the corresponding red light emitted can effectively compensate for the missing red light component in white light-emitting diodes(WLEDs). The operating temperature of WLED typically hovers around 150 degrees Celsius. At such temperatures, the luminous efficiency of fluorescent powders remains remarkably resilient, peaking at 94.84 % relative to room conditions. Even when the temperature surges to 200 degrees Celsius, the luminous efficiency of fluorescent powders persists at an impressive 88.87 %. The energy band gap of Ca3Gd0.3(AlO)3(BO3)4:0.7Eu3+ is up to 5.05 eV, which further demonstrates its excellent thermal stability. Ca3Gd0.3(AlO)3(BO3)4:0.7Eu3+ phosphor used in the WLED device emits warm white light (CCT = 3628 K, CRI = 87.4). As a result of these results, the phosphor can be used as an excellent red light component in pc-WLEDs.

Study on the Preparation and Fluorescence Properties of Sr3Y(PO4)3: Dy3+/Tm3+

In this article, the high temperature solid-state method is adopted to synthesize Sr3Y(PO4)3: Dy3+/Tm3+ fluorescent powder. By testing and characterizing the X-ray diffraction (XRD) as well as the exciting and emitting spectrum, analyzing fluorescence lifetimes and chromaticity coordinates, we studied phase structures and optical properties of Sr3Y(PO4)3: Dy3+/Tm3+. Results of XRD show the Sr3Y(PO4)3 fluorescent powder is synthesized. Along with the increasing of adulterate concentrations, XRD peaks show overall shift. Under excitation by 352 nm, Sr3Y(PO4)3: Dy3+ exhibits blue and yellow emitting peaks at 485 nm and 575 nm, which, respectively, correspond to 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions. And under excitation by 360 nm, Sr3Y(PO4)3: Tm3+ exhibits blue emitting peak at 455 nm, which corresponds to the 1D2→4F3 transition. The luminous intensity maximum of Sr3Y(PO4)3: Dy3+ occurs at 485 nm when the Dy3+ molar percentage of adulterate concentration is 0.05. The luminous intensity maximum of Sr3Y(PO4)3: Tm3+ occurs at 455 nm when the Tm3+ molar percentage of adulterate concentration is 0.05. According to the CIE, it is proved that Sr3Y(PO4)3: Dy3+ is a single matrix phosphor that can produce cold white light, and Sr3Y(PO4)3: Tm3+ is a mixed matrix phosphor that can produce blue light.

Highly effective red phosphor for warm white LEDs without rare earth elements

The use of red fluorescent powder derived from nitrides and oxides in warm white LEDs is a pressing concern due to its lower quantum efficiency. Fluoride red phosphors activated by Mn4+ ions show promising potential for application in white light-emitting diodes (LEDs) due to their distinctive narrowband red emission and broad blue excitation, along with the relatively mild synthesis conditions required. However, the quantum efficiency of early Mn4+-doped fluoride phosphors was not optimal, highlighting the importance of identifying a suitable preparation method and matrix. Here, we introduce an efficient and thermally stable red fluoride phosphor, Cs2SiF6:Mn4+, which demonstrates a remarkable quantum efficiency of 98.32 % achieved through ion exchange techniques. However, even at a temperature of 423 K, the luminous intensity still maintained at 95 % of that under room temperature conditions. By incorporating Cs2SiF6:Mn4+ as a red emitter, a stable 10 W high-power warm white LEDs with a luminous efficiency of approximately 126.1 lm/W can be realized. These findings underscore the significant potential of the red phosphor Cs2SiF6:Mn4+ in advancing high-performance, high-power warm white LEDs.

Cucurbit[8]uril-modulated discrete pyrene dimers fluorescent sensor for nitroaromatic compounds and latent fingerprints visualization

As a promising class of luminescent materials, π-conjugated organic aromatic molecules are usually subject to aggregation-caused quenching (ACQ) effect, which limits their wide application. Currently, obtaining structurally visualized solid luminescent materials of polycyclic aromatic hydrocarbons (PAHs) without complex synthetic purification steps remains a challenging topic. Herein, we focus on the supramolecular assembly strategy to constructed a solid fluorescent material (HPTS@Q[8]@Rb+) by co-assembling cucurbit[8]uril (Q[8]) with 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) and rubidium ions based on the coordination and outer surface interactions of Q[8]. HPTS@Q[8]@Rb+ exhibited good fluorescence properties with quantum yields of 2.28 % and 73.15 % in solid state and aqueous suspensions, respectively, providing a good sensing platform for nitroaromatic compounds (NACs), especially for 2,4,6-trinitrophenol (PA) and 4-nitroaniline (4-NA) with remarkable quenching constants (KSV=4.06×104 M−1 for PA and KSV=2.95×104 M−1 for 4-NA) in working range of 0–3.33×104 M and 0–5.0×104 M, respectively. Moreover, a fluorescent fingerprint powder was prepared by combining montmorillonite (MMT) for high-resolution visualization of latent fingerprints (LFPs) without substrate limitation. This study demonstrates the synthesis of Q[n]-based fluorescent material, the anion-rich aromatic compounds can be used as potential moieties for assembly with Q[n], providing a facile and promising approach to develop PAHs-based luminescent materials. This supramolecular self-assembly strategy provides a fundamental design principle for the creation of diverse functional crystalline solid materials.

A magnetic and excited state intramolecular proton transfer fluorescent powder for latent fingermark visualization

A magnetic and excited state intramolecular proton transfer fluorescent powder for latent fingermark visualization