Detection Of Latent Fingerprints Research Articles

Latent Fingerprint Development by Brick Powder

In forensic investigations, the relationship between the criminal, the victim, and the crime scene can be firmly established through the detection of latent finger marks. Fingerprints are avital and unique identity of a person. These are impressions left by the friction ridges of a human finger on contact with any surface. Many unique characteristics in the human body like a fingerprint, DNA, palm prints, iris patterns, voices, etc. So, Fingerprint is a unique characteristic of the human body, and every human’s different fingerprints between identical twins. As we know friction ridges develop in a 3-4 month of gestation duration time. Mayer, a German doctor, and anatomist were the first to write that friction ridge skin is unique. The fingerprint is the most important evidence at the Crime scene and identification of the criminal. Fingerprint identification is a method of identification using the impression formed by the minute ridges seen on the fingertips. Fingerprint has certain individual characteristics that are unique. Latent fingerprints are most generally seen prints from the crime scene. Such prints are obtained when natural oils and perspiration existing between the fingertip ridges are transferred to a surface by any contact. Latent prints are invisible and are much harder to detect and preserve. In this research paper, a new method for the development of Latent fingerprints is used that’s brick powder. The brick powder is used in various Porous and Non-porous surfaces like plastic glass, ordinary mirror, matchbox, painted wall, writable CD, wooden substrate, currency note, door handle, floor surface, book cover, sunglasses, and mobile glass card for development of latent fingerprint impression.

Pilot Study on the Visualization of Latent Fingerprints and Naked Eye Detection of Hg2+ and Zn2+ Ions in Aqueous Media Using Ninhydrin-Based Thiosemicarbazone.

Here, we described a cheap and effective chemosensor (NHPyTSC) that can distinguish Hg2+ and Zn2+ ions from other metal ions and evaluated this phenomenon using several spectroscopy techniques. With the addition of mercury and zinc ions, the proposed chemosensor in particular showed noticeable changes in color and absorption spectra. Additionally, by including EDTA in the NHPyTSC-Hg2+ and NHPyTSC-Zn2+ solutions, colorimetry readings can be reversed. We developed a molecular-scale sequential information processing circuit and presented the "writing-reading-erasing-reading" and "multiwrite" behaviors in the form of binary logic based on the great reversibility of this process. Moreover, by sequentially adding Hg2+, Zn2+, and EDTA, NHPyTSC imitates a molecular keypad lock and molecular logic gates. Density functional theory (DFT) investigations provided more evidence of the Hg2+ and Zn2+ ions' ability to attach to NHPyTSC. The most interesting part of this work is that a study on the latent fingerprint detection of the powder compound revealed that NHPyTSC exhibits good adherence and finger ridge features without background stains. When compared to black and white fingerprint powders, it is discovered that the NHPyTSC powder produces results that are remarkably clear on the majority of surfaces. This demonstrated their potential for real-world use, particularly in the area of criminal investigations.

Single phased vivid red-emitting CaLa2ZnO5:Eu3+ nanophosphor: WLEDs, visualization of latent fingerprints and anti-counterfeiting applications

A novel class of cutting-edge materials known as photoluminescent (PL) nanophosphors (NPs) based on inorganic compounds has the potential to be used in a variety of industries, including chemo sensors, optical devices, drug delivery systems, anticounterfeiting inks (AC), and bioimaging. In the present work, we report a simple propellent combustion method for the preparation of CaLa2ZnO5:Eu3+ (1–9 mol%) (CLZO:Eu) NPs. The optimized powders are utilized for strategic applications such as white light emitting diodes (WLEDs), latent Finger Print (LFP) detection and anti-counterfeiting (AC) applications. According to the PL spectral profiles, the dazzling red emission has been observed at 626 nm (5D0→7F2) from the CLZO:Eu NPs under the excitation of 395 nm. The ideal activator concentration is determined to be 5 mol%, and the quadrupole-quadrupole interactions are attributed for the concentration quenching that resulted from the over doping. The CIE coordinates (x-y) are determined to be (0.6206, 0.3732) for CLZO:5Eu NPs. The correlated colour temperature (CCT) value for the optimized sample is determined to be between 2000 and 5000 K, indicating that it may be a more suitable red component for warm white light applications. The fabricated PL NPs for AC labels exhibited strong fluorescence emission and good stability, under UV light, different chemical environments, and ambient environments making them suitable for a variety of uses, including environmentally friendly PL inks for anti-counterfeiting technologies. CLZO:5Eu NPs, on the other hand, can clearly distinguish between grooves and ridges and recognize the detail of levels 1–3. The overall results clearly showed that, the present material has great potential for multilevel anticounterfeiting strategies to achieve high-security encryption.

Approaches for the Detection of Latent Fingermarks on Deceased Human Bodies

Approaches for the Detection of Latent Fingermarks on Deceased Human Bodies

In-situ formation of oleic acid amide ligand boosts persistent luminescence of zinc gallate nanoparticles toward efficient latent fingermark detection

Cr3+-doped zinc gallate (ZnGa2O4:Cr3+, ZGOC) nanomaterials feature with near-infrared emission and long afterglow properties. However, simultaneously controlling nanoparticle size and afterglow performance of ZGOC remains very challenging. A novel organic amine-stimulated solvothermal synthesis method for preparing ZGOC nanoparticles was demonstrated in this paper. Controllable synthesis of ZGOC nanoparticles was realized for uniform particle size distribution and excellent afterglow properties via adding different amines in organic phase system. Among them, by the triethylamine-stimulated solvothermal method, ZGOC nanoparticles are subsphaeroidal and narrow size distributed with an average particle size of about 11 nm. The near-infrared luminescence intensity of the nanoparticles was enhanced more than 7 times. The underneath organic amines stimulation mechanism was clarified as the in-situ formation of oleic acid amide ligand, consequently, enhancing the afterglow properties via combination results of surface defects passivation and ligand antenna effect. Furthermore, uniform particle size distribution and excellent afterglow properties make the prepared nanoparticles show great visualization in latent fingermark detection. The current finding of in-situ formation of oleic acid amide ligand offers guidance for the controllable synthesis of nanoparticles by the organic amines-stimulated solvothermal method.

Red emissive nanocomposite with high quantum yield for ultrasensitive and selective detection of latent fingerprints

Level 1–3 minutiae of latent fingerprints (LFPs) play essential roles in the identification of individuals. The level 3 details of sweat pores are especially important for accurate LFPs recognition, as they can provide microscopic features. Fluorescent materials with high quantum yield and red emission are advantageous in the LFPs detection, due to the associated potential of elevated sensitivity and contrast. Herein, a highly fluorescent red emissive nanocomposite material (PPDCDs@ZIF-8) was successfully prepared by combining carbonized polymer dots of PPDCDs with zeolitic imidazolate framework ZIF-8 in situ. The obtained material displays a strong and stable red emission at solid state with the maximum peak located at 630 nm, and the fluorescence quantum yield of PPDCDs is significantly improved from 17.8% to 43.5% after conjugation with ZIF-8. This nanocomposite material was successfully applied to detect LFPs on glass, metal, marble and other substrates with ultrahigh sensitivity. The obtained fluorescent images clearly revealed the detailed LFPs features from level 1 to level 3. Therefore, PPDCDs@ZIF-8 possesses great potential applications in crime scenes as it provides an easy and accurate strategy to visual the sweat pores in LFPs.

Synthesis and spectroscopic characterization of fluorescent 3-acetyl-4-hydroxy coumarin for biomedical and latent fingerprint applications

The fluorescent 3-acetyl-4‑hydroxy coumarin (AcHyC) development for DNA binding affinity and latent fingerprint detection under UV illumination has not yet been adequately researched. In this sense, this work presents the fabrication and characterization of AcHyC for DNA binding and latent fingerprint applications. Based on electronic absorption spectroscopy, AcHyC was bound to DNA with a significantly high binding constant (2.9 × 106M−1). The interaction of AcHyC with DNA has also been examined using molecular docking analysis, which supports earlier spectroscopic data. The photoluminescence emission and the lifetime of AcHyC were measured. AcHyC exhibited intensive yellowish-green luminescence with spectacular visual emission under unharmful UVA and UVB excitation. Based on the highly luminescent character of AcHyC, latent print details, including their characteristic three levels, have been identified from various forensic substrates (non-porous, semi-porous, and porous).

Novel Red‐Emitting Gd3BW1‐xMoxO9 : Eu3+ Phosphor with High Thermal Stability for Application in UV‐Excited WLEDs and Rapid Visualization of Latent Fingerprints

AbstractRare‐earth‐doped inorganic luminescent materials are widely used in white light‐emitting diodes (WLEDs), lasers and forensic sciences due to their outstanding optical characteristics. However, it is still a challenge to obtain such materials with better thermal stability for application in WLEDs on account of their serious thermal quenching properties. In addition, there is still room for improvement in some respects such as higher sensitivity and contrast for application in latent fingerprint development. Herein, a series of novel Gd3BW1‐xMoxO9 : Eu3+ phosphors have been synthesized via high‐temperature solid‐state reaction process. Compared with different Mo6+ ions doping concentrations, Gd3BW0.7Mo0.3O9 : Eu3+ phosphor has optimal photoluminescence properties. Meanwhile, the emission intensity of Gd3BW0.7Mo0.3O9 : Eu3+ phosphor is over 3 times higher than that of commercial red phosphor. More impressive is its excellent resistance against thermal quenching; when heated up to 150 °C, the Gd3BW0.7Mo0.3O9 : Eu3+ phosphor still preserves about 98 % emission intensity of that at room temperature. Furthermore, the latent fingerprints (LFPs) developed by Gd3BW0.7Mo0.3O9 : Eu3+ phosphor exhibited the excellent visualization on various nonporous substrates, and level 1–3 features were well identified with high contrast and sensitivity. The obtained results suggested that the as‐prepared phosphor has great potential for application in both WLEDs and latent fingerprint detection.

Microwave-assisted synthesis of GdOF: Eu3+/Tb3+ ultrafine phosphor powders suitable for advanced forensic and security ink applications

The rare-earth-doped inorganic ultrafine oxyfluoride host matrices in forensic science, especially in latent fingerprint detection and anti‐counterfeiting applications, were still unexplored and may replace the existing technology owing to its high sensitivity. Herein, GdOF: Eu3+/Tb3+ ultrafine red and green phosphors were synthesized via a rapid, green microwave-assisted hydrothermal method at 150 °C. The phosphors synthesized by this novel method possess good luminescent intensity for the hypersensitive 5D0→7F2 transition of Eu3+ and 5D4→7F5 transition of Tb3+ ions as compared to the phosphors prepared via other conventional methods such as co-precipitation synthesis, sol–gel synthesis, and microwave-assisted co-precipitation synthesis. Further, an enhancement in the luminescent intensity of the ultrafine phosphor was noticed when the microwave parameters and pH values were tuned. The optimized red and green phosphors having high luminescence intensity, good color purity, and high quantum yields of 89.3%, and 71.2%, respectively, were used for the visualization of latent fingerprints on various substrates. These promising phosphors exhibited excellent visualization regardless of the background interference and limit the risk of duplication and are highly reliable. The security inks developed using these phosphors are highly efficient for anti-counterfeiting applications. These multifunctional properties of investigated phosphors can be explored for security applications.

Stimuli-responsive color-tunable BaLa2ZnO5:Bi3+ phosphor for the encryption and authentication of security patterns and latent fingerprint detection

Due to the outstanding optical qualities, stimulation-responsive luminous materials have drawn a lot of attention in the anti-counterfeiting application. In this work, the feasibility of applying BaLa2ZnO5:Bi3+ (BLZO:Bi3+) (0.5–4.0 mol%) phosphor, to multiple stimuli anti-counterfeiting (AC) and latent fingerprint visualization (LFP) is explored and discussed. The prepared luminous security ink from the optimized phosphor is effectively used for the multiple stimuli AC under 325, 355 and 375 nm excitation wavelengths. The results show that the fabricated luminous security ink is highly stable in ultraviolet (UV) light, various chemical environments, and ambient conditions. In addition, powder dusting method is utilized for LFPs detection on porous, non-porous and semi-porous surfaces under different excitation wavelengths. The multilevel features of the phosphor-attached LFP could be identified clearly in all the surfaces. The high-resolution LFPs imaging by scanning electron microscope (SEM) pictures, providing us more precise details on the width, distance, distribution, and forms of fingerprint (FP) pores. All the results reveal that the phosphor is a good potential choice for AC and LFP detection.

A cost-effective intense blue colour cobalt doped gahnite pigment for latent finger print, cheiloscopy and anti-counterfeiting applications

Alanine is used as a novel fuel in the solution combustion method (SCS) to produce nanocrystalline Co2+ (0.25–5 mol%) doped gahnite (ZnAl2O4: ZAO) nano pigments (NPs). A thorough investigation was conducted to comprehend the interaction of dopant (Co2+) and ZAO host matrix, as well as the influence of doping on their structural, optical, and luminescence properties. The powder samples were thoroughly characterized using XRD, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Photoluminescence (PL) spectroscopic techniques. SEM micrographs of clearly exhibit the formation of dense particles, voids, and pores in the sample. In addition, tiny aggregates were detected on the surface of more prominent clusters. The nominal composition of Zn, Al, Co and O was assessed using Energy Dispersive X-Ray Analysis (EDS). The optimized ZAO:5Co2+ phosphor powder demonstrated levels 1–3 fingerprint (FP) features and groove patterns (types 1–5) of lip print that can be clearly recognised, with excellent resolution and contrast, under 320 nm UV light. The appropriate thickening agent and defoamer were added to blue pigment during fabrication to generate anti-counterfeiting (AC) inks that mark on multiple surfaces with high resolution without spreading or tracing. The preceding results suggest that the ZAO:Co2+ NPs can serve as a significant candidate for the detection and individualization of latent fingerprints (LFP), lip prints (LP) and anti-counterfeiting applications.

Sensitive Fingerprint Detection Using Biocompatible Mesoporous Silica Nanoparticle Coating on Non-Porous Surfaces

In recent years, the development and application of biocompatible nanomaterials in the detection of fingerprints have become a major focus for the forensic sector and crime investigators. This study aims to synthesize biocompatible silica nanoparticles (Si NPs) through cost-effective green methods and will be used to detect a latent fingerprint on a non-porous surface. As a type of environmentally friendly nanomaterial, Si NPs were prepared via an oil–water mixed micro-emulsion templating (MET) approach. Their characteristics and optical properties were measured using EDX-SEM, HR-TEM, FTIR, XRD, and UV–visible absorption. The biocompatibility of the synthesized Si NPs in terms of cell viability was observed, even at high concentrations (83.46% and 75.28% at 20 and 50 mg mL−1, respectively). The developed Si NPs were tested on different surfaces, including plastic, glass, silicon, steel, and soft plastic for the detection of crime scene fingerprints. In this research, it was found that the Si NPs were of the size of 100–150 nm. Results confirmed that synthesized mesoporous Si NPs can be used to detect latent fingerprints on multiple non-porous surfaces and were easy to detect under a UV lamp at 395 nm. These findings reinforce the suggestion that the developed Si NP coating has a high potential to increase sensitive and stable crime traces for forensic latent fingerprint detection, even in packaged food with different packaging surfaces.

Designing orange-red emitting luminescent platform for data security and information encryption based Sm3+ doped BLAO phosphor

Due to the features of great difference and invariability, latent fingerprint (LFP) and lip print (LP) detection has grown to be a vital part of criminal investigation. Due to its environmental friendliness, powder dusting is now the method of choice for visualizing LFPs. The uses of this technology are severely constrained by essential flaws like limited resolution, low sensitivity, and high background interference. To address these issues, a novel orange red emitting BaLaAlO4:Sm3+ (1–5 mol %) (BLAO:Sm) phosphor has been fabricated via solution combustion route. The 4G5/2 → 6H7/2 transition of Sm3+ ions caused the phosphor to generate intense orange-red light at 601 nm under stimulation at 402 nm. The optimal Sm3+ concentration in BLAO is 2 mol % (BLAO:2Sm). The International Commission on Illumination evaluated the colour coordinates (CC), correlated colour temperature (CCT), and colour purity (CP) values based on the photoluminescence emission (PLE) profiles. The acquired CC and the typical National Television System Committee (NTSC) coordinates are compared. Additionally, the usefulness of the phosphor is assessed for the powder dusting technique to detect fingerprints (FPs) on various surfaces. The level 1–3 structure of LFPs and the distinct features of lip prints (LPs) are clearly visible utilizing the BLAO:2Sm phosphor under 402 nm, UV illumination. Fluorescent phosphor is fabricated with the necessary thickening agent in order to create AC inks that mark on various surfaces with high resolution without spreading and tracing. When exposed to UV light, the above ink's drawn design instantly developed and is illuminated with vivid orange red fluorescence emission. The results revealed that the optimized phosphor can garner significant interest for use in personal identification, and security encoding.

New fluorescent electrospun polymer materials containing phenothiazinyl carboxylate metal salts for versatile latent fingerprint detection

In this work the synthesis and structural characterization by NMR and single crystal X-Ray Diffraction of four new phenothiazine-carboxylate salts (lithium, sodium, potassium, and calcium salts respectively) is reported together with a description of their use as contrast agents in the fabrication of new fluorescent electrospun polyvinylpyrrolidone nanomaterials suitable for latent fingerprint (LFP) detection were reported.The optical properties of the new fluorophores and fluorescent electrospun polymer (FEP) nanomaterials (λem = 448–467 nm) were evaluated by UV–Vis absorption/emission spectroscopy. Fluorescence lifetime imaging microscopy (FLIM) analysis indicated an intense and uniform fluorescence in solid state, with fluorescence lifetime increasing significantly for FEP material (8–11 ns) in comparison to the correspondent blank fluorophore. Scanning electron microscopy (SEM) investigations revealed the size of the new FEP materials situated in the nanometric range with fiber or granular morphology.The newly synthesized FEP nanomaterials were successfully tested in the detection of LFP from various smooth or porous surfaces such as glass, metal, plastic, ceramic or wood and demonstrated a versatile capability of direct visualization in UV and daylight of enhanced LFP, as well as of primary lifts collected by gently pressing the polymeric mats on the tested surfaces. The quality of the collected LFPs images was determined mainly by the fluorophore structure, best visualization results being obtained with the phenothiazine sodium carboxylate salt. The new FEP nanomaterials appear suitable for highly accurate forensic investigations, supporting a direct analysis by photography, an expeditive and non-hazardous alternative for avoiding the disadvantages of techniques such as dusting or chemical treatment currently applied in the dactyloscopic identification of a suspect person at the crime scene.

Ultralong Room-Temperature Phosphorescence of Boron Carbon Oxynitride Nanodots Encapsulated in Pyrophosphate in Dry and Wet States for Fingerprint Detection and Information Protection

Room-temperature phosphorescence (RTP) materials have attracted wide interest due to their long lifetime and free from background autofluorescence. Nevertheless, simultaneous activation of stable long-lived RTP emission in both solid and aqueous phases remains a tremendous challenge. Herein, a molten salt method to synthesize boron carbon oxynitride nanodot-based RTP composites (BCNO nanodots@pyrophosphate) was carried out by employing pyrophosphate as the inert shell for BCNO nanodots. The BCNO nanodots@pyrophosphate1 with the average size of 3.69 nm show bright-green RTP because the introduction of phosphorus is beneficial to the intersystem crossing process and increases the RTP emission. What is more, whether in solid or aqueous dispersion, BCNO nanodots@pyrophosphate1 retains good phosphorescent properties with a high phosphorescence quantum yield (29.5% and 18.6%) and a long lifetime (1.39 and 1.29 s), which lasts over 15 s to the naked eye. This is the first report on BCNO nanodots with RTP in aqueous solution. The unique RTP characteristics allow BCNO nanodots@pyrophosphate as a hopeful indicator for detection of latent fingerprints with high contrast and multilevel information protection.

Preparation, characterization, and application of a red phosphor Ca2InTaO6:Eu3+ in w-LEDs and latent fingerprint detection

Eu3+-doped Ca2InTaO6 phosphors were synthesized by a high-temperature solid-state reaction. Their crystal structure, composition, phase purity, photoluminescence (PL) properties, and thermal quenching mechanism were investigated in this experiment. The band gap of Ca2InTaO6 (3.87 eV) classifies it as an indirect band gap material. X-ray diffraction results confirm the good phase purity of the synthesized material has good phase purity. The Ca2InTaO6 lattice has an orthorhombic structure, which includes the Pnma(No. 62) space group. After being excited at 395 nm, Ca2InTaO6:0.40Eu3+ phosphor showed a red emission peak at 613 nm (5D0→7F2 transition). The optimal doping concentration of Ca2InTaO6:xEu3+ phosphor is x = 0.40. Moreover, Ca2InTaO6:0.40Eu3+ phosphor has a color purity of 99.9%, an internal quantum efficiency (IQE) of up to 90.69% and a thermal activation energy (Ea) of 0.36 eV. The prepared white light-emitting diode (w-LED) possesses satisfactory color rendering index (Ra = 88.3), correlation color temperature (CCT = 5748 K), and Commission International de L′Eclairage (CIE) coordinates (0.327, 0.339). The levelsⅠ-Ⅲ characteristics of the latent fingerprint (LFP) created by Ca2InTaO6:Eu3+ phosphor can also be clearly reflected. These experimental results show that Ca2InTaO6:Eu3+ phosphor can be applied in w-LED production and LFP detection.

Fluorophores-rich natural powder from selected medicinal plants for detection latent fingerprints and cyanide.

Forensic science is currently fast-growing for the development detection of the latent fingerprint. Currently, chemical dust quickly enters the body through touch or inhalation and will be affected by the user. In this research, a study on the comparison of natural powder from four species of medicinal plants (Zingiber montanum, Solanum Indicum L., Rhinacanthus nasutus, and Euphorbia tirucall) for the detection of latent fingerprints is carried out that has fewer adverse effects on the user's body by using such natural substances instead. In addition, the fluorescence properties of the dust have been found in some natural powder for sample detection and appear on multi-colored surfaces to show that the latent fingerprints are more pronounced than ordinary dust. In this study, medicinal plants have also been applied to detect cyanide, as it has been known that it is hazardous for humans and can be used as a poisonous compound to kill someone. The characteristics of each powder have also been analyzed using naked-eye detection under UV light, Fluorescence spectrophotometer, FIB-SEM, and FTIR. All the powder obtained can then be used for high potential detection of latent fingerprints on the non-porous surface with their specific characteristics and trace amounts of cyanide using turn-on-off fluorescent sensing method.

Delving into the multifunctionality of Sr2NaMg2V3O12via RE3+ substitution for dual-mode temperature sensing, latent fingerprint detection and security inks

Multifunctionality of vanadate garnet phosphors in latent fingerprint detection, security inks, and dual-mode temperature sensing.

Annealing-assisted optimization for persistency of afterglow of SrAl2O4:Eu2+/Dy3+ microparticles for forensic detection.

In the present work, Eu2+/Dy3+ ions doped/co-doped into persistent SrAl2O4 microparticles have been developed through solid-state synthesis followed by homogenization and particle size reduction in a ball milling device. These particles have shown a broad and long-persistent afterglow around the 528 nm wavelength of electromagnetic radiation through a broad excitation at around 400 nm. The luminescence intensity was optimized through the selection of different annealing temperatures in the range of 1100 °C to 1500 °C, with intervals of 100 °C. Several structural and optical characterization techniques, such as XRD, SEM, FTIR, thermogravimetric analysis, and photoluminescence, were utilized to judge the preparation and ability of these particles in possible applications in latent fingermark detection on various difficult surfaces. The persistency and stability of these particles were calculated using a digital lux meter.

Improving automated latent fingerprint detection and segmentation using deep convolutional neural network

Improving automated latent fingerprint detection and segmentation using deep convolutional neural network