AIEE-Active Green Fluorescence Imaging Technique for Latent Fingerprint Application.

Latent fingerprint imaging is a crucial tool for national security and crime recognition, requiring environmentally sustainable, nontoxic materials. To address this need, we have developed a green fluorescence-emitting material, THCHO, that binds effectively to latent fingerprints, enabling clear, high-resolution visualization. The solution produces strong green fluorescence that highlights fingerprint imprints with exceptional detail and contrast. The material is applicable across various substrates, making it efficient for on-site visualization. The synthesized organic conjugated material THCHO rapidly visualizes precise fingerprint substructures within 5 s using a simple spray method. It maintains high contrast and low interference across different substrates, such as glass, aluminum foil, plastic, and ironware, even in diverse backgrounds. Additionally, the THCHO material demonstrates high stability, retaining its fluorescence imaging capabilities for up to 35 days and after water washing. This is the first report of using a conjugated organic thiophene material for latent fingerprint fluorescence imaging, suggesting potential applications in other fields.

Fluorescent Tetraphenylethylene-Based Cerium Metal-Organic Frameworks for White-Light-Emitting Diodes.

Discovery of highly efficient and thermal stable phosphors is the focus of the studies in phosphor-converted white light-emitting diodes (LEDs). Herein, a tetraphenylethylene-based cerium metal-organic framework (SYNU-2) was synthesized and characterized. The intricate architecture of SYNU-2 shows an overall 3D → 3D 2-fold interpenetration framework. SYNU-2 exhibited good luminescence properties, and its latent fingerprint developer was prepared, which showed good fluorescence and stability under ultraviolet (UV) radiation. It is worth noting that a prototype WLED device can be designed using SYNU-2 and red phosphors (Ca,Sr)AlSiN3:Eu2+ with CIE coordinates of (0.33, 0.33) at an applied 3 V bias.

Luminescence, temperature sensing and Judd-Ofelt analysis of Bi2Mo3O12:Eu3+ phosphors and the application in latent fingerprint visualization.

Eu3+-activated materials have garnered significant attention due to their outstanding optical characteristics. In this work, the sol-gel method was successfully used to prepare Bi2Mo3O12 phosphors doped with different amounts of Eu3+. The generated samples were identified as orthorhombic Bi2Mo3O12 with a scheelite-like structure by X-ray diffraction analysis of the crystal structure. The sample's morphology and size were examined using scanning electron microscopy and transmmission electron microscopy, which revealed irregular block morphology and tens to hundreds nanometers scale dimension. From the analysis of the concentration-dependent luminescence intensity of Eu3+, it was confirmed that the exchange interaction was responsible for the quenching of 5D0 fluorescence of Eu3+. When excited at 374 nm, the phosphor emitted brilliant red light, with the highest emission occurring at 616 nm (5D0→7F2 transition), and the calculated color coordinates of the sample were (0.663, 0.336). By examining the temperature dependence of the emission spectra, the temperature sensing performance of the sample and the thermal quenching behavior of Eu3+ luminescence was explored. Furthermore, the optical transition property of Eu3+ was investigated by using the emission spectra and fluorescence lifetime within the context of Judd-Ofelt theory. Ultimately, latent fingerprint visualization of the sample on various object surfaces was studied, thanks to the intense luminescence and small particle size of the Bi2Mo3O12:Eu3+ phosphor. The results indicated that the sample can clearly display the different hierarchical features of fingerprint on different object surfaces.

Live Cell Imaging Studies on Orange Emitting Thiazole-Pyridone Azo Fluorophore and Its Latent Fingerprints, Computational, Electrochemical Sensing for Dopamine Detection.

The fluorescent materials have sparked a lot of research interests due to their unique electronic, optical and chemical characteristics. Here, we are intended to present a simple and facile synthesis of novel orange emitting thiazole-pyridone fluorescent tag (TPFT) by a simple diazo coupling reaction and the structural elucidation was carried out by IR, NMR (1H and 13C), UV-Vis, photoluminescence and HR-MS spectrometry. The solvatochromic behaviour of the TPFT offered crucial information about the formation of hydrazone and azo tautomeric forms. The DFT simulations are computed to calculate HOMO-LUMO energy gap (3.028 eV) of TPFT along with MEP and RDG analyses. Comprehensive LFP visualization is revealed under both normal and UV light conditions (365 nm). The cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to analyse the electrochemical behaviour of the TPFT-modified glassy carbon electrode (MGCE) and exhibited a lower detection limit of 7.89 × 10-8 M (S/N = 3) with a linear range of 0.5-8.0 µM for DA detection. The live-cell imaging study of TPFT showed a strong blue emission at 453 nm, which generally indicates the existence of fluorescence stability.

Rotor proliferation promotes high-brightness AIE of iridium emitter accomplishing high-contrast luminous imaging of latent fingerprints to level 3 details.

Luminous imaging of latent fingerprints (LFPs) necessitates the possession of high-brightness aggregation-state luminescence by developers to ensure sufficient imaging contrast and resolution. A novel strategy involving incremental rotor modification is presented for AIE activation of the iridium developer. The rotor proliferation prominently improves the rotational activity of groups and facilitates high-efficiency RIM, thereby prompting the AIE activation of iridium developer with high luminous efficiency. Subsequently, a prompt, high-contrast, and robust LFP imaging protocol is developed utilizing the high-brightness AIE-active iridium developer. This innovative protocol realizes the luminous imaging and quantification of microscopic features in fingerprint ridges and furrows, including ridge widths, edge morphology of ridges, included angles, pores, and pore pitches with exceptional imaging contrast and refined detail resolution. Moreover, it allows for accurate identification of individual traits across diverse substrates without any pre-/post-processing to LFPs. The high-brightness AIE-active iridium developer provides outstanding aging resistance to developed fingerprints, thereby strongly supporting the acquisition, transfer, and preservation of fingerprint evidence. The luminous imaging protocol of LFPs based on high-brightness AIE exhibits robust adaptability to actual scenes and offers a premium scheme for facilitating forensic investigation.

Using the refractive index of latent fingerprints for the quantification and characterisation of sample deposition.

Latent fingerprints (LFPs) are predominantly used for personal identification, but in recent years research has shown their potential for drug screening. Despite this there is no standardised collection method to allow accurate drug test interpretation. We sought to help address this by characterising different variables related to sweat deposition in LFPs as the knowledge is limited. A series of experiments were conducted firstly to validate a novel tool called the Ridgeway (Intelligent Fingerprint Ltd. UK) to quantify the amount of sweat deposited from a LFP using the refractive index (RI). A significant positive correlation was observed between the Ridgeway score (Rs) and LFP mass [r = 0.868, p < 0.01]. The Rs was used as means to investigate optimal sampling to characterise sample deposition for drug screening purposes. It was found with a consistent disposition pressure (300 - 400 g) and surface (glass slide) no significant difference was observed between the left and right index finger [left: p = 0.938; right: p = 0.838]. Significantly higher Rs [p<0.01] were obtained when 10 cumulative LFPs were deposited compared to a single LFP, suggesting a larger sweat quantity. We also wanted to investigate optimal eccrine sweat sampling to confirm drug ingestion over drug contamination of the fingerprint. We found that wearing gloves did not significantly improve mean difference in Rs when compared to no gloves [p = 0.239]. To produce eccrine only LFPs, external contamination (e.g. sebaceous sweat) needs to be removed. Soap with lint free tissue was significantly better for this compared to antibacterial hand gel [p<0.01]. Our findings showed that the Ridgeway tool effectively quantified LFPs at the point of deposition using a refractive index and enabled us to establish conditions for consistent LFP sampling.

Mechanofluorochromic behaviors and latent fingerprint detection of triphenylamine-based compounds with mono-/bis-BF2 fluorophores.

To better understand the relationship between molecular structure of the mono-/bis-BF2-core compounds and mechanofluoroboron behaviors, two pyridine-based difluoroboron compounds with triphenylamine group (TPA-ts-BF2 and TPA-ts-2BF2) were designed and successfully synthesized, which TPA-ts-BF2 including a BF2 fluorophore and TPA-ts-2BF2 containing the bisBF2 fluorophores. Based on the photophysical properties measurements results, it was found that TPA-ts-2BF2 had more excellent intramolecular charge transfer characteristics than that of TPA-ts-BF2, and exhibited significant aggregation-induced emission activity, however, TPA-ts-BF2 displayed typical aggregation-caused quenching phenomenon. Meanwhile, the emission spectrum of the solid powders of TPA-ts-2BF2 was red-shifted 52 nm after grinding, that of TPA-ts-BF2 was red-shifted 46 nm, which was resulted from crystalline state switching to amorphous state. According to the theoretical calculations, we conjectured that TPA-ts-BF2 with uncoordinated amide linkage moiety had a tendency to forming a more twisted conformance and higher molecular polarity, which made that mechanofluorochromic behavior was worse than that of TPA-ts-2BF2. Additionally, TPA-ts-2BF2 was applied to latent fingerprint detection due to its prime aggregation-induced emission property.

Non-destructive and simultaneous development and enhancement of latent fingerprints on stainless steel based on the electrochromic effect of electrodeposited manganese oxides.

Latent fingerprints, as one of the most frequently encountered traces in crime scene investigation and also one of the largest sources of forensic evidence, can play a critical role in determining the identity of a person who may be involved in a crime. Due to the invisible characteristic of latent fingerprints, exploring efficient techniques to visualize them (especially the ones resided on metallic surfaces) while retain the biological and chemical information (e.g., touch DNA) has become a multidisciplinary research focus. Herein we reported a new and highly sensitive electrochemical interfacial strategy of simultaneously developing and enhancing latent fingerprints on stainless steel based on synchronous electrodeposition and electrochromism of manganese oxides in a neutral aqueous electrolyte. By utilizing a specially designed device for electrochemical testing and image capture, a series of electrochemical measurements, physical characterization and image analysis have been applied to evaluate the feasibility, development accuracy and enhancement efficacy of the proposed electrochemical system. The qualitative and quantitative analysis on the in situ and ex situ fingerprint images indicates that the three levels of fingerprint features can be precisely developed and effectively enhanced. Forensic DNA typing has also been performed to reveal actual impact of the proposed electrochemical system on subsequent analysis of touch DNA in fingerprint residues. The ratio of detected loci after electrochemical treatment reaches up to 98.5 %, showing non-destructive nature of this fingerprint development and enhancement technique.

Use of automated quality assessment algorithms in fingermark detection research - Application to IND/Zn vs DFO.

When developing detection techniques for fingermarks, the detected fingermarks must be evaluated for their quality to assess the effectiveness of the new method. It is a common practice to compare the performance of the new (optimized) technique with the traditional or well-established ones. In current practice, this evaluation step is carried out by a group of human assessors. A new approach is applied in this paper and consists of using algorithms to perform this task. To implement this approach, the comparison between IND/Zn and DFO has been chosen because it has already been the subject of many articles published in recent years and a consensus exists on the superiority of IND/Zn over DFO. The quality of 3'600 fingermarks developed using both detection techniques was assessed automatically using two algorithms: LQM (Latent Quality Metric) and ILFQM (Improved Latent Fingerprint Quality Metric). The distribution of quality scores was studied for both detection techniques. The results showed that fingermarks detected with IND/Zn received higher scores on average than fingermarks detected with DFO, which is in line with the consensus in the literature based on human assessment. The results of this research are promising and shows that automated fingermark quality assessment is an efficient and viable way to comparatively assess fingermark detection techniques.

Visualization of latent fingerprints using fluorescence lifetime imaging on paper emitting strong fluorescence.

Latent fingerprints were successfully visualized using fluorescence lifetime imaging (FLIM) on paper which emits strong fluorescence with a lifetime close to that of fingerprints and thus from which it is difficult for time-resolved spectroscopy to visualize fingerprints. Latent fingerprint samples on paper were excited using a 450 nm or 532 nm nanosecond pulsed-laser, and time-resolved fluorescence images were obtained at a delay time of 6-16 ns in intervals of 1 ns, to the excitation pulse. The excitation beam was expanded using a lens, and the fluorescence from the fingerprints was captured using an intensified CCD camera. Because of the large fluorescence intensity of the background paper of approximately two to four orders of magnitude larger than that of the fingerprint, the fingerprint was not visualized on each fluorescence image by time-resolved spectroscopy. However, the fingerprint was visualized in a FLIM image constructed using a series of the fluorescence images for the case with the fluorescence intensity of the background paper being four orders of magnitude larger than that of the fingerprint. The difference in fluorescence lifetime in the FLIM image of the visualized fingerprint and background paper was in the order of 0.1 ns, which was an order of magnitude smaller than the inherent fluorescence lifetime of a few nanoseconds for the fingerprints and paper. It was demonstrated that, at a background fluorescence intensity with a certain order of magnitude larger than that of fingerprints, FLIM has the potential to visualize latent fingerprints which cannot be visualized by time-resolved spectroscopy.

Salicylaldehyde built fluorescent probe for dual sensing of Al3+, Zn2+ ions: Applications in latent fingerprint, bio-imaging & real sample analysis.

This Schiff base chemosensor (SNN) detected dual ions, Al3+ and Zn2+ ions selectively. Fluorescence spectrum investigations showed that Al3+ ions increased fluorescence intensity, notably at 493 nm. Introducing Zn2+ ions caused a significant blue shift of roughly ∼65 nm at a wavelength of 434 nm, resulting in a notable change in fluorescence intensity. When binding Al3+/Zn2+ ions, the SNN receptor uses three methods. Inhibition of photoinduced electron transfer (PET), excited state intramolecular proton transfer (ESIPT), and restriction of CN isomerization. The jobs plot method found that SNN + Al3+ and SNN + Zn2+ complexations had a 1:1 stoichiometry. DFT, LC-HRMS, and 1H NMR titration confirm this conclusion. The probe SNN's limit of detection (LOD) for Al3+/Zn2+ ions was 3.99 nM and 1.33 nM. Latent fingerprint (LFP), food samples, pharmaceutical products, and E. coli pathogen bio-imaging have all used the SNN probe to identify Al3+ and Zn2+ ions.

Colloidal Polymer Nanoparticles as Smart Inks for Authentication and Indication of Latent Fingerprints and Scratch.

An environmentally friendly smart ink was developed by incorporating fluorescein into functionalized poly(methyl methacrylate) (PMMA) nanoparticles synthesized using an emulsifier-free emulsion copolymerization approach. The functional comonomers of 2-(dimethylamino)ethyl methacrylate (DMAEMA), acrylamide, hydroxyethyl methacrylate, and glycidyl methacrylate in 10 wt % with respect to methyl methacrylate were used to obtain the functionalized colloidal PMMA nanoparticles. Functional groups of the latex nanoparticles were characterized by Fourier-transform infrared spectroscopy. Field emission scanning electron microscopy results showed that all of the latex nanoparticles have nearly spherical morphologies with variations in size and surface smoothness due to the presence of different comonomers. Ultraviolet-visible and fluorescence spectra indicated that the fluorescein-doped latex nanoparticles containing the DMAEMA comonomer had the highest absorbance and fluorescence intensity. In the alkaline media, fluorescein turns to a dianion, showing a red shift and increased absorbance in the UV-vis spectroscopy. In addition, the electron inductive characteristics of the tertiary amine groups result in enhancing the conjugation of fluorescein molecules and increasing the fluorescence intensities. Therefore, the colloidal nanoparticles with amine functional groups were used in the formulation of a smart ink with applications in securing documents and fingerprints, encrypting banknotes and money, detecting latent fingerprints, crafting anticounterfeiting paper, and eventually providing optical detection and indication of surface scratches.

Dual-Emissive Mn-Doped Lead Halide Perovskite Nanocrystals as Background-Suppressed Latent Fingerprint Detection Probes.

Diverse strategies have been developed to visualize latent fingerprints (LFPs) that are undetectable by the naked eye. Among them, fluorescence-based approaches have emerged as an attractive method for enabling high-resolution LFP imaging. However, the use of fluorescent probes for LFP detection remains challenging due to cumbersome processing, low selectivity, and high background interference. Here, we demonstrate highly efficient, sensitive, and background-free LFP detection with dual-color emission arising from manganese (Mn)-doped lead halide perovskite (CsPb(Cl1-yBry)3) nanocrystals (NCs). The resulting bright, fluorescent, solid-state nanopowder (NP) permits the visualization of LFP ridge structures and the resolution of level 1-3 LFP features. The dual-color emission of the Mn-doped perovskite NP provides a simple, robust, and effective route to overcome background interference, thereby increasing the resolution and sensitivity of the LFP detection. The combination of the high quantum efficiency and dual emission of Mn-doped perovskite NP offers great potential for forensic science.

Barium Lanthanum Oxide Nanosheets in Photocatalytic and Forensic Applications: One-Pot Synthesis and Characterization.

The present work elucidates the fabrication of Barium Lanthanum Oxide nanosheets (BaLa2O4 NSs) via a simple one-pot precipitation method. The acquired results show an orthorhombic crystal system with an average crystallite size of 27 nm. The morphological studies revealed irregular-shaped sheets stacked together in a layered structure, with the confirmation of the precursor elements. The diffused reflectance studies revealed a strong absorption between 200 nm and 350 nm, from which the band-gap energy was evaluated to be 4.03 eV. Furthermore, the fluorescence spectrum was recorded for the prepared samples; the excitation spectrum shows a strong peak at 397 nm, attributed to the 4F7/2→4G11/2 transition, while the emission shows two prominent peaks at 420 nm (4G7/2→4F7/2) and 440 nm (4G5/2→4F7/2). The acquired emission results were utilized to confirm the color emission using a chromaticity plot, which found the coordinates to be at (0.1529 0.1040), and the calculated temperature was 3171 K. The as-prepared nanosheets were utilized in detecting latent fingerprints (LFPs) on various non-porous surfaces. The powder-dusting method was used to develop latent fingerprints on various non-porous surfaces, which resulted in detecting all the three ridge patterns. Furthermore, the as-synthesized nanosheets were used to degrade methyl red (MR) dye, the results of which show more than 60% degradation at the 70th minute. It was also found that there was no further degradation after 70 min. All the acquired results suggest the clear potential of the prepared BaLa2O4 NSs for use in advanced forensic and photocatalytic applications.

Effects of solvent-based adhesive removal on the subsequent dual analysis of fingerprint and DNA.

The combined approach of classical fingerprinting and DNA profiling is a powerful tool in forensic investigations of latent "touch" traces. However, little attention has been paid to the organic solvents frequently used in dactyloscopic laboratories to facilitate the separation of adhesive evidence prior to fingerprint development and downstream effects on subsequent DNA profiling. In the present study, we tested a selection of adhesive removers (n = 9) and assessed their potential impact on DNA recovery and amplification by PCR. Thereby, we identified and characterized novel PCR inhibitors. All investigated chemicals contain volatile organic compounds that evaporate under normal indoor atmospheric conditions. Exposure to certain solvents resulted in increased DNA degradation, but only if evaporation was prevented. A series of adhesive-removal experiments were conducted with prepared mock evidence (self-adhesive postage stamps affixed to paper envelope) to investigate the impact of treatment time and the location of applied traces on DNA recovery and dactyloscopy, respectively. Due to the early onset of print decomposition, we found that only a short treatment time was compatible with the development of fingerprints on the adhesive side of a stamp. Solvents also removed DNA from the adhesive surface, thus resulting in a marked shift in the substrate distribution of recovered DNA from the stamp to the envelope, but not in the reverse direction. Furthermore, we observed that treatment with conventional fingerprint reagents lead to a significant reduction in the amounts of DNA recovered from stamps, while the additional use of adhesive removers did not significantly enhance this effect.

High-definition and robust visualization of latent fingerprints utilizing ultrabright aggregation-induced emission of iridium developer.

Creation of AIEgens with high brightness is compactly related to acquiring optimum AIE capabilities and still faces challenges. This study proposes an ingenious structurally regulative approach for preparing ultrabright AIEgens, taking iridium complexes as the model. The incremental rotational activity of substituents obtained by fine adjustment of the stereoscopic configuration efficaciously activates the AIE of iridium complexes and synchronously imparts high-brightness luminescence. Subsequently, benefitting from the ultrabright AIE, high-resolution visualization of latent fingerprints (LFPs) is achieved on diverse substrates by transient immersion in a solution of the AIE-active iridium complex (Ir3) for 60 s. The LFPs stained by Ir3 are integral and distinct enough to possess level 1-3 detail features, which allow precisely realizing personal identification. The LFP photograph emerges inconspicuous attenuation of contrast when aged under ambient light for 10 days and then being continuously irradiated with high-power ultraviolet light for 1 h, reflecting extraordinary aging resistance. Notably, the ultrabright AIE of Ir3 with room-temperature phosphorescence feature successfully achieves enhanced visualization of local fingerprint details with ultrahigh contrast. This LFP visualization protocol based on the ultrabright AIEgens is practical and provides a reliable solution for forensic investigations in actual scenarios.

Enhance photoluminescence properties of Ca-Eu:Y2O3@SiO2 core-shell nanomaterial for the advanced forensic and LEDs applications.

The divalent (Ca2+)-doped Eu:Y2O3@SiO2 core-shell luminescent nanophosphors have been synthesised by a cost-effective combustion technique. Various characterizations were carried out to confirm the successful formation of the core-shell structure. The TEM micrograph reveals the thickness of the SiO2 coating over Ca-Eu:Y2O3 as ∼25 nm. The optimal value of silica coating over the phosphor has been obtained as 10 vol%(TEOS) of SiO2, with this value increasing fluorescence intensity by 34 %. Phosphor exhibits CIE coordinates as x = 0.425, y = 0.569 and a CCT value as ∼2115 K with color purity and the respective CRI of 80 % and 98 %, respectively, which make the core-shell nanophosphor suitable for warm LEDs, and other optoelectronic applications. Further, the core-shell nanophosphor has been investigated for the visualisation of latent finger prints and as security ink. The findings point towards the prospective future application of nanophosphor materials for anti-counterfeiting purposes and latent finger prints for forensic purposes.

Highly efficient ferric ion sensing and high resolution latent fingerprint imaging based on fluorescent silicon quantum dots.

Expanding the application of silicon based luminescent materials is a fast-growing interdisciplinary field. Herein, a novel fluorescent bifunctional probe based on silicon quantum dots (SiQDs) for highly sensitive Fe3+ sensing and high-resolution latent fingerprint (LFP) imaging was subtly devised. The SiQD solution was mildly prepared using 3-aminopropyl trimethoxysilane as the silicon source and sodium ascorbate as the reductant, showing green emission at 515 nm under UV irradiation with a quantum yield of 19.8%. As a highly sensitive fluorescent sensor, the SiQD was demonstrated to have a highly selective quenching with Fe3+ in the concentration range of 2-1000 µM with the LOD of 0.086 µM in water. The quenching rate constant and association constant of the SiQDs-Fe3+ complex was calculated to be 1.05 × 1012 mol/s and 6.8 × 103 L/mol, respectively, suggesting a static quenching effect between them. Moreover, to achieve high-resolution LFP imaging, a novel SiO2@SiQDs composite powder was further fabricated. The SiQDs were covalently anchored on the surface of silica nanospheres to conquer aggregation-caused quenching for the high-solid fluorescence. In the demonstration of LFP imaging, this silicon based luminescent composite exhibited high developing sensitivity, high selectivity and high contrast, indicating its practical value as a fingerprint developer at crime scenes.

Probabilistic Fingermark Quality Assessment with Quality Region Localisation.

The assessment of fingermark (latent fingerprint) quality is an intrinsic part of a forensic investigation. The fingermark quality indicates the value and utility of the trace evidence recovered from the crime scene in the course of a forensic investigation; it determines how the evidence will be processed, and it correlates with the probability of finding a corresponding fingerprint in the reference dataset. The deposition of fingermarks on random surfaces occurs spontaneously in an uncontrolled fashion, which introduces imperfections to the resulting impression of the friction ridge pattern. In this work, we propose a new probabilistic framework for Automated Fingermark Quality Assessment (AFQA). We used modern deep learning techniques, which have the ability to extract patterns even from noisy data, and combined them with a methodology from the field of eXplainable AI (XAI) to make our models more transparent. Our solution first predicts a quality probability distribution, from which we then calculate the final quality value and, if needed, the uncertainty of the model. Additionally, we complemented the predicted quality value with a corresponding quality map. We used GradCAM to determine which regions of the fingermark had the largest effect on the overall quality prediction. We show that the resulting quality maps are highly correlated with the density of minutiae points in the input image. Our deep learning approach achieved high regression performance, while significantly improving the interpretability and transparency of the predictions.

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.