Visualization Of Latent Fingerprints Research Articles

Dansyl fluorophore functionalized hierarchically structured mesoporous silica nanoparticles as novel latent fingerprint development agents.

A nanostructured hybrid material based on mesoporous silica nanoparticles (MCM-41) functionalized with chitosan and a fluorescent dye (dansylglycine), designated MCM-41@Ch@DnsGly, was synthesized and characterized with a view to its application for the visualization of latent fingerprints. These nanoparticles were applied as latent fingerprint developers for marks on surfaces of diverse chemical composition, topography, optical characteristics, and spatially variant nature, typical of forensically challenging evidence. For quality assessment of the enhanced fingermarks, the developed images were analyzed holistically using the UK Home Office scale, forensic protocols and, in terms of their constituent features (minutiae), using forensic software. Across a substantive collection of marks deposited on chemically diverse surfaces and subject to complex environmental and temporal histories, 94% of the enhanced images presented sufficient minutiae for comparison with model dactyloscopy images. This novel nanomaterial presents enhanced performance with significant promise for superior exploitation by forensic practitioners in the acquisition and analysis of crime scene evidence.

Dysprosium doped SrCeO3 nanophosphors for advanced photochemical applications: Synthesis, characterization, photo-assisted dye degradation and latent fingerprint visualization

The present work investigates the novel potential of Sr(1-x)CeO3: xDy3+ (x = 1–9 mol%) nanoparticles, fabricated through Solution Combustion method using citric acid as fuel. The as-fabricated samples were thoroughly characterised using a variety of techniques to obtain structural, morphological, and optical data. Powder X-ray diffraction (PXRD) examination revealed the presence of an orthorhombic crystal structure (Pnma) matching PDF card #01-083-1156. Tauc's plot evaluating band gap energy utilizing absorption spectra reveals a range of 3.4 eV–4.2 eV with refractive index ranging from 0.64 to 1.22. Using Field Emission Scanning Electron Microscopy (FESEM), it was possible to see a coral-like aggregation for the host and initial concentration of Dy3+ ions, and a porous structure for higher concentrations. With an average particle size of 38.20 nm, a comprehensive Transmission Electron Microscopy (TEM) study demonstrates the fused aggregation structure. Moreover, quantifiable evidence of the precursors presence is provided by X-ray Photoelectron Spectroscopy (XPS). For the as-fabricated samples, photoluminescence investigations were carried out. Two strong peaks with a dominating 4F9/2 → 6H13/2 diploe-dipole transition was seen in the observed emission spectra under 366 nm (6H15/2 → 6P7/2) excitation. These peaks are positioned at 573 nm (4F9/2 → 6H13/2) and 478 nm (4F9/2 → 6H15/2). Under UV light, two cationic dyes, Rhodamine-B (Rh–B) and Methylene Blue (MB), were photo-catalytically degraded using the prepared sample (SCD5). According to 0th and 1st order kinetics, the observed data show evidence of effective degradation up to 89.64 % (Rh–B) and 78.86 % (MB) at 80th minute. In addition, the impact of several analytical parameters on the percentage degradation of Rh–B and MB dyes was investigated. These parameters included catalyst changes, dye dosage, and scavenger effect. The produced nanoparticles were used to create latent fingerprints on two non-porous surfaces: glass and aluminium. The results clearly showed that on both surfaces a type-III level of detection was attained. To summarise, the outcomes indicate that Sr(1-x)CeO3: xDy3+ nanoparticles that have been synthesized can be used for advanced forensic applications as well as for the degradation of dye pollutants.

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.

High-contrast multi-surface imaging of latent fingerprints using color-tunable YOF:Tb3+,Eu3+ ultrafine nanophosphors with high quantum yield.

Visualization of latent fingerprints (LFPs) using conventional powders has faced challenges on multicolor surfaces. However, these challenges are addressed by the advent of fluorescent powders in LFP detection, and they have redefined the effectiveness of the powder dusting method. In this study, color-tunable YOF:Tb3+,Eu3+ nanophosphors were examined for LFP recognition and were evaluated for their practicality on different types of surfaces. Under 254 nm UV irradiation, the LFPs developed using these nanophosphors showed clear and distinct ridge patterns with level 1, 2, and 3 details. The ultrafine particles of these nanophosphors adhered to the ridge patterns and replicated the minutiae of the LFPs. Meanwhile, the variation of the Tb3+/Eu3+ ratio demonstrated multicolor fluorescence emission from the nanophosphors, which provided better contrast between the ridge patterns on complex surfaces. Furthermore, the high luminescence quantum yield of the nanophosphors ensured high-resolution fluorescence images of the LFPs with a well-defined pattern that was recognizable even without any microscope or sophisticated instrumentation.

Enhancement imaging of developed latent blood fingerprints using TOF-SIMS

As one of the most common types of evidence in violent cases, blood fingerprints play an important role in identifying suspects. Typically, Latent blood fingerprints from a crime scene require the application of chemical development reagents followed by photographing to visualize the ridge detail. However, conventional development techniques are not effective in the visualization of poor latent blood fingerprints due to the formation conditions. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a surface analysis technique that combines high mass resolution and high spatial resolution to recover through mass spectrometry imaging (MSI) to reveal fingerprints that are invisible to the naked eye, especially conventional visualization methods. In this study, an enhancement method for latent blood fingerprints was established by analyzing blood fingerprints that showed poor visibility using conventional methods (acid yellow, amido black 10B, tetramethylbenzidine) on plastic sheets, aluminum foil, various papers, and other objects. Additionally, blood samples were diluted with distilled water at concentration gradients of 1:5, 1:10, 1:20, and 1:100 to test the method's sensitivity. Latent fingerprints of blood that aged 14, 30, and 54 days were also examined. Results showed that this method not only enhances the development of fingerprints under challenging conditions but also allows for the recovery of incomplete fingerprints and the separation of overlapping fingerprints. Compared to conventional methods, this approach significantly improves the development effect of latent blood fingerprints while maintaining universality, reliability and practicality.

Latent fingerprint visualization with the novel white fluorescent fingerprint powders

Based on carbazole derivatives, a new fluorescent dye G-D was constructed. White fluorescent fingerprint powder was constructed by proportionally blending montmorillonite with G-D and the previously synthesized dyes (B-D and R-D). White fluorescent fingerprint powder is obvious in the dark and can be subjected to minimal fluorescent background interference. The white fluorescent fingerprint powder was successfully used to develop latent fingerprints left on various surfaces, including glass, tin foil, marble, acrylic plate with bright fluorescence, painted wood and coins. Impressively, the white fluorescent fingerprint powder also has excellent applications in developing aged fingerprints and replication. For complex criminal investigation activities, the white fingerprint powder with high resolution, wide applicability and real-time development is a competitive visualization means.

Multimodal responsive Dy3+, Li+ activated Gd2MgTiO6 phosphors for ideal wLED, potent anti-counterfeiting, fingerprint visualization, and encryption coding

The Gd2MgTiO6 is an infant luminescence host that portrays eclectic applications in displays, security devices, and forensic studies. The perovskites are synthesized by facile combustion method, decreasing the synthesis conditions from 1573 K, 5 h to 1173 K, 4 h, from conventional routes. The phosphors are then activated with Dy3+ ions, giving photoluminescence emission in the blue, yellow, and red regions of the visible spectrum owing to (4F9/2 → 6H15/2), (4F9/2 → 6H13/2), and (4F9/2 → 6H11/2) transitions respectively. Further, monovalent Li+, divalent Sr2+, or trivalent Sm3+ ions are co-doped in the crystal matrix, which chiefly enhances the optical and crystalline properties for Li+ sensitization. Under 351 nm excitation, these samples show CIE coordinates (0.3290, 0.3313), color temperature 5759 K, color rendering index 86, and color purity of 2.5 %; signifying ideal white light emission for wLED with quantum efficiency 43 %. Under 980 nm excitation, these phosphors gave noble red emission, which can be effectually applied as a level 3 latent fingerprint visualization tool in criminology. The white and red emissions on UV and NIR excitation respectively are combined for potent anti-counterfeiting security ink and encryption coding; which marked a new methodology for the multifunctional application of a single phosphor matrix.

Ultra-bright green emitting Sr2MgSi2O7:Tb3+ nanophosphors: unveiling multi-security applications in anti-counterfeiting, flexible films, optical thermometry and latent fingerprint visualization

In this study, we synthesized facile green-emitting Sr2MgSi2O7:Tb3+ (1–11 mol %) nanophosphors (SMSO:Tb3+ NPs) using a solid-state reaction method. Characterization through X-ray diffraction (XRD) revealed a tetragonal crystal structure in the as-synthesized SMSO:Tb3+ NPs. Crystallographic data obtained from Rietveld refinements identified the specific sites of Tb3+ ions in the host material. Chemical and photo-luminescent properties are explored using X-ray photo-electron spectroscopy (XPS) and Photoluminescence (PL) spectroscopy, respectively. The NPs exhibited vibrant green emission at 547 nm, attributed to the Tb3+ ions' 5D4→7F5 transition, with a high quantum yield of 63.10 %. Optimal doping concentration is determined as 7 mol % (SMSO:7 Tb3+), overcoming concentration quenching primarily due to dipole-dipole (d-d) interaction. Impressively, SMSO:7 Tb3+ NPs demonstrated a correlated colour temperature (CCT) of 5549 K, colour purity (CP) of 91.60 %, and excellent colour stability. These phosphors are effectively applied in latent fingerprints (LFPs) development, revealing distinct ridge features useful for personal identification. Additionally, SMSO:7 Tb3+ NPs, combined with soluble PVA, are used to create a transparent anti-counterfeiting (AC) film, exhibiting intense green emission under UV 365 nm light. Notably, the film flexibility, durability, and foldability enhance its applicability in AC techniques. This study showcases SMSO:Tb3+ NPs as versatile luminous platforms with applications in flexible displays, high-colour quality lighting, fingerprint (FP) visualization, and anti-counterfeiting.

Multi‐Purpose Fluorescent Powder: Development of Latent Fingerprints and Glove Prints

AbstractA novel hydroxy benzothiazole based yellow fluorescent powder (labelled as 2‐SiO2) was prepared by adsorption of 2 on silica (4 % w/w) for visualization of latent fingerprints (LFPs) and glove prints using powder dusting method. The solid‐state spectrum of 2‐SiO2 shows emission peak at 550 nm with CIE‐1931 coordinates ( ) of 0.42, 0.50 and yellow colour purity is 58.6 %. The high fluorescence of 2 in the solid‐state could be attributed to AIE+ESIPT features. Due to high fluorescence of 2‐SiO2 (4 % w/w) powder, fluorescence imaging of LFPs on a variety of porous and non‐porous substrates including glove prints, up to levels 1–3, without any post‐treatment has been achieved. The 2‐SiO2 showed strong interaction with D‐Glucose, urea and lactate components present in sweat. The practical applications of 2‐SiO2 powder have been demonstrated by analysis of LFPs, development of LFPs at different temperatures; aged, stained fingerprints and preservation of developed fingerprints for documentation purposes.

Enhanced photocatalytic, photoluminescence and fingerprint properties of Dy3+ ions doped BaZrO3 nanopowders for multifunctional applications

In the present investigation photoluminescent, photocatalytic and advanced forensic applications of hydrothermally prepared BaZrO3:Dy3+ (1–9 mol%) nanopowders were studied in detail. Fresh green Aloe Vera (AV) gel was used as capping agent for the preparation of NPs. The pure cubic phase was observed by powder X-ray diffraction (PXRD) profiles. Fourier transform infrared (FTIR) was utilized to investigate the functional groups present in the prepared NPs. The modification in surface morphology was investigated by using Field emission scanning electron microscope (FESEM) images. The grain size was evaluated by utilizing transmission electron microscope (TEM) images and found to be around 48 nm. Further, with the help of high-resolution TEM (HR-TEM) images the interplanar distance was calculated and found to be 0.32 nm. Photoluminescence (PL) studies were carried out in detail using excitation and emission spectra. The maximum intensity was detected for peak 388 nm ascribed to 6H15/2 → 4I13/2 + 4F7/2 of Dy3+ transition under 574 nm emanation wavelength. The obtained emanation spectra consist of 3 characteristics peaks of Dy3+ ions at 480, 574 and 666 nm attributed to 4F9/2→ 6H15/2, 4F9/2→ 6H13/2 and 4F9/2→ 6H11/2 respectively. The PL intensity increases up to 7 mol% dopant ion weight and afterwards it decreases due to concentration quenching phenomena. The dipole–dipole interaction was responsible for this quenching. The color coordinates results in white emission witnessed from the Commission International de I'Eclairage (CIE) and correlated color temperature (CCT) diagrams. The average CCT value was observed around 4836 K. Further, the color purity (CP) and external quantum efficiency (QE) was estimated and found to be 86 % and 64 % respectively. The photocatalytic degradation activity was also studied for the prepared powders and found that, the optimum degradation was observed till 180 min. The kinetics studies revealed that, the present powders were in agreement with the 0th order with estimated ko = 0.015 with R2 value of 0.98 respectively. The powders were also explored for their latent fingerprint (LFP) visualization on various porous and non-porous surfaces and found that, the powders exhibited all types of fingerprint ridge details including the 3rd type such as sweat pores and scar. The observed all outcomes specify that, the prepared powders can be used as a potential candidate for the fabrication of white LEDs (wLEDs), excellent photocatalyst and fingerprint visualization.

DNA recovery after sequential processing of latent fingerprints on black polyethylene plastic.

Latent fingerprints on plastic substrates can be visualized by using sequential treatments to enhance the contrast between the fingerprint residues and underlying substrate; however, the extent to which these processes affect subsequent DNA analysis is mostly unknown. Latent fingerprints deposited on black plastic by one donor were visualized with single-process fingerprint powders (i.e., white powder, bichromatic powder, or bichromatic magnetic powder) or sequential treatments (i.e., laser → reflected ultraviolet imaging system (RUVIS) → CA fuming → RUVIS → Rhodamine 6G, Ardrox, and MBD (RAM) or CA fuming → RAM/laser → bichromatic magnetic powder). Samples were examined after the addition of each treatment. DNA was collected using cotton swabs, extracted, quantified, and amplified. DNA yields, peak heights, number of alleles obtained, and percentage of DNA profiles eligible for CODIS upload were examined. Latent fingerprints processed with the laser and up to three sequential treatments generated DNA profiles with significantly higher peaks heights than those of the untreated samples. Fingerprints processed with the laser and up to two sequential treatments generated DNA profiles with significantly more alleles. All methods beginning with laser enhancement generated more CODIS-eligible profiles. Additional research is needed to determine the extent to which initial laser enhancement impacts the success of downstream DNA profiling results. Although DNA profile development is not guaranteed due to the variable quantities of DNA contained within latent fingerprints, the selection of an appropriate latent fingerprint visualization method could maximize both fingerprint detection and the generation of CODIS-eligible DNA profiles.

A novel 3D-printed portable electroplating device enhances latent fingerprints on metal substrates

This work introduces a 3D-printed portable electroplating device for the visualization of latent fingerprints (LFPs) on metallic substrates. An electroplating solution of Ag+–Cu2+ in a deep eutectic solvent (DES) is used. The electroplating is performed by two electrodes equivalent to an anode (+) and a cathode (−). The cathode is connected to the metal surface with the magnetic or alligator clip for carrying the LFP. The anode is connected to cotton dipped in the electroplating solution. The device was optimized in terms of the electroplating solution composition, and electroplating potential, current, and time. The device produced images with good resolution, revealing LFP ridges in minute detail of more than 12 points. The device also exhibited good repeatability and images were assessed against guidelines from the Centre for Applied Science and Technology (CAST) and the International Fingerprint Research Group (IFRG). The developed device could be applied to visualize LFPs in forensic investigations.

Eu3+ hypersensitive transition modulation: A novel red garnet phosphors with high color purity and excellent thermal stability

Luminescent materials have garnered interest as alternative dusting powders for the enhanced visualization of latent fingerprints (LFPs) due to their pronounced emission, vivid fluorescence, and high contrast capabilities. This study introduces, for the first time, a novel red garnet phosphor doped with Eu3+ in the Ca3Zr2SiGa2O12 (CZSG) matrix. By substituting Eu3+ ions for Ca2+ ions, the hypersensitive transition of the Eu3+ ions is modulated, leading the phosphor to exhibit an outstanding color purity, nearing 100 %. The optimal emission intensity of the phosphor is achieved with a Eu3+ concentration of 12 %. Notably, it showcases high thermal stability, retaining 96.5 % of its intensity at 423 K, and has a high activation energy of 0.4385 eV. This phosphor has displayed its potential in latent fingerprint analysis, as evidenced by its effective application in visualizing latent fingerprints.

De Novo Green Fluorescent Protein Chromophore-Based Probes for Capturing Latent Fingerprints Using a Portable System.

Rapid visualization of latent fingerprints, preferably at their point of origin, is essential for effective crime scene evaluation. Here, we present a new class of green fluorescent protein chromophore-based fluorescent dyes (LFP-Yellow and LFP-Red) that can be used for real-time visualization of LFPs within 10 s. Compared with traditional chemical reagents for LFPs, these fluorescent dyes are completely water-soluble, exhibit low cytotoxicity, and are harmless to users. Level 1-3 details of the LFPs could be clearly revealed through "off-on" fluorescence signal readout. Additionally, the fluorescent dyes were constructed based on an imidazolinone core and so do not contain pyridine groups or metal ions, which ensures that the DNA is not contaminated during extraction and identification after the LFPs are treated with the dyes. Combined with our as-developed portable system for capturing LFPs, LFP-Yellow and LFP-Red enabled the rapid capture of LFPs. Therefore, these green fluorescent protein chromophore-based probes provide an approach for the rapid identification of individuals who were present at a crime scene.

A study on development of fingerprint powders using natural sources for latent fingerprint visualization on non-porous surfaces

A study on development of fingerprint powders using natural sources for latent fingerprint visualization on non-porous surfaces

Visualization of latent fingerprints based on composites of dye-doped cellulose with red emissive fluorescence

Visualization of latent fingerprints based on composites of dye-doped cellulose with red emissive fluorescence

Investigating Fe-doped yttrium oxide nanophosphors for enhanced latent fingerprint visualization and deep learning analysis

In the study, synthesized Fe3+ doped yttrium oxide nanophosphors (Y2O3:Fe NPs, 1–11 mol%), including structural, microstructural, chemical state, optical, thermal, and photoluminescence properties, are extensively studied. An optimized 7 mol % Fe doped Y2O3 NPs powder is used to develop latent fingerprints on various surfaces through a simple powder dusting method. The developed fingerprints are visible under 254 nm UV light. The research also analyzes several pore properties: size, shape, number, position, type, and inter-distance. A fingerprint recognition deep learning model based on the YoLOv8 algorithm was developed and employed for analyzing both single and overlapped fingerprints. These highly effective NPs are also used to create a transparent anti-counterfeiting (AC) ink that exhibits AC properties when exposed to UV light, and their physical and chemical stability opens novel applications in the AC field. The optimized Y2O3:7Fe3+ NPs are an excellent luminous platform for solid-state lighting, AC, and dermatoglyphics applications.

Nanoscale Aluminate-Based Afterglow Materials from Byproducts of Aluminum–Water-Based Hydrogen Production for Anticounterfeiting and Latent Fingerprint Visualization

Nanoscale Aluminate-Based Afterglow Materials from Byproducts of Aluminum–Water-Based Hydrogen Production for Anticounterfeiting and Latent Fingerprint Visualization

Visualizing Fingerprints on Porous Objects by an Optical Sensor Minimally Destructive to DNA Based on Aggregation‐Induced Emission

AbstractDevelopment of latent fingerprints (LFPs) at the scene played the important role in forensic investigations by reconstructing crime trajectory and individualizing suspect. In this work, the optical sensor named TPE‐LL with aggregation‐induced emission property was constructed and used in LFPs visualization. The sensor exhibited a satisfactory linear relationship to tryptophan (Trp) in the range of 1–20 nM with the low detection limit of 0.15 nM. The samples were collected from 60 volunteers, with a total of 7200 impressed samples and 160 natural samples. Significantly, the high‐resolution fingerprints images with high fidelity and contrast containing pore features were obtained from impressed samples left on porous object for 15 days. Meanwhile, the relative complete STR typing profiles of deposited DNA were obtained and the identification rate of DNA after the develop process was 76.5 %, suggesting that the method was low destructive to DNA. The results indicated that the sensor provided promising perspectives on solving the current technical problems in the field of forensic science and technology

Upconversion luminescence based temperature sensing properties and anti-counterfeiting applications of GdNbO4:Tm3+/Yb3+ phosphor

Pure monoclinic phase GdNbO4:Tm3+/Yb3+ phosphor was prepared using solid state reaction method for upconversion emission, optical thermometry, latent fingerprints visualization and anti-counterfeiting applications. The prepared phosphor exhibits colour tunability with temperature variation (from blue to almost white) and good suppression of thermal quenching. The temperature sensing characteristic from thermally and non-thermally coupled levels of Tm3+ ion were investigated using the fluorescence intensity ratio (FIR) approach. The result shows that the sensitivity for non-thermally coupled level is about ∼ 45 times higher than thermally coupled level. Latent fingerprint detection on various surfaces and anti-counterfeiting ink application were also shown upon 980 nm laser diode excitation. Above results indicate that the prepared GdNbO4:Tm3+/Yb3+ phosphor have applicability in the field of frequency upconversion, optical thermometry, color tunable devices, latent fingerprint visualization and anti-counterfeiting applications.