FLUORESCENCE COMPOSITE MATERIAL FOR LATENT FINGERPRINT IMAGING AND METHOD THEREOF

Abstract

An embodiment herein provides a fluorescence composite material for latent fingerprint imaging. The fluorescence composite material includes (i) a thiophene-based emissive material that has aggregation induced emission enhancement (AIEE) property, and the thiophene-based emissive material is conjugated with aldehyde to optimize for green fluorescence emission with pH stability, and (ii) a polymer matrix including polyethylene glycol (PEG) in a concentration ranging from 10% to 50%, wherein 10% to 50% of PEG is synthesized by mixing at least one of 1 gram (g), 3g, 5g, 7g, or 9g of PEG in 20 ml volume. The thiophene-based emissive material is mixed with the PEG to synthesize a fluorescence composite material, which the PEG enables the binding of the thiophene-based emissive material with grease phase of grooves and meadows of a fingerprint due to intramolecular rotation provide by the PEG for improved latent fingerprint imaging and fluorescence emission. The thiophene-based emissive material exhibits green fluorescence under ultraviolet (UV) light, thereby enhancing the visual contrast between the fingerprint ridges and furrows. The PEG acts as a viscosity modifier to improve the adherence of the thiophene-based emissive material to latent fingerprints and enabling improved coverage of fingerprint details. FIG. 1

Specification

Description:BACKGROUND
Technical Field
[0001] The embodiments herein generally relate to thiophene based fluorescent materials and latent fingerprint imaging, more particularly to a fluorescence composite material for latent fingerprint imaging and a method for preparing the fluorescence composite material for latent fingerprint imaging.
Description of the Related Art
[0002] Numerous fingerprint imaging techniques, such as iodine fumigation, ninhydrin, silver nitrate soaking, and powder methods, have been utilized. However, these methods are characterized by complex procedures, high costs, and low background contrast.
[0003] Capturing three-level fingerprint details (including ridge structure and pore details) remains challenging with these techniques. Furthermore, these methods often suffer from common issues such as dust hazards, loss of fingerprint details, and background fluorescence caused by material accumulation around latent fingerprints. Some techniques, such as carbon dot dusting, even involve toxic metal ions.
[0004] To overcome these drawbacks, researchers have explored potent AIE-active fluorogenic probes. While red, yellow, and blue-emitting molecules have been reported for imaging, they have limitations. For instance, a red near-infrared (NIR) luminescence probe developed for mobile phone-based fingerprint imaging almost captured the necessary details, but the human eye's sensitivity to red light is inferior to green, and the pore details are still unclear.
[0005] Green fluorescence imaging significantly enhances the visual recognition of latent fingerprints, aiding in accurate fingerprint identification. Although polymer nanoparticles with greenish-yellow emission have been employed to visualize second-level fingerprint details, third-level details, including pores, are not clearly achieved.
[0006] Recently, a green-emitting fluorophore for third-level fingerprint detail imaging was developed by Rui Tian et al., but concerns about sustainability and cytotoxicity in AIE materials used for LFP imaging remain unresolved.
[0007] The primary motivation behind the new material design is to minimize cytotoxicity, especially considering its environmental disposal. Thus, a material with wide pH stability has been developed.
[0008] In existing scenarios, various materials for latent fingerprint (LFP) imaging have been established, but their imaging retention capacity and pH stability are significantly limited. To address these issues, there is a need to synthesize and develop a green emissive material with Aggregation-Induced Emission Enhancement (AIEE) properties and wide pH stability.
SUMMARY
[0009] In view of the foregoing, an embodiment herein provides a fluorescence composite material for latent fingerprint imaging. The fluorescence composite material includes (i) a thiophene-based emissive material that has aggregation induced emission enhancement (AIEE) property, and the thiophene-based emissive material is conjugated with aldehyde to optimize for green fluorescence emission with pH stability, and (ii) a polymer matrix including polyethylene glycol (PEG) in a concentration ranging from 10% to 50%, wherein 10% to 50% of PEG is synthesized by mixing at least one of 1 gram (g), 3g, 5g, 7g, or 9g of PEG in 20 ml volume. The thiophene-based emissive material is mixed with the PEG to synthesize a fluorescence composite material, which the PEG enables the binding of the thiophene-based emissive material with grease phase of grooves and meadows of a fingerprint due to intramolecular rotation provide by the PEG for improved latent fingerprint imaging and fluorescence emission.
[0010] The thiophene-based emissive material exhibits Aggregation-Induced Emission Enhancement (AIEE), which significantly improves the visibility of latent fingerprints through bright green fluorescence emission. The thiophene-based emissive material is designed with wide pH stability, making it suitable for use across various environmental conditions without compromising performance. The inclusion of polyethylene glycol (PEG) in the composite material facilitates strong binding of the thiophene-based material to the greasy phase of fingerprint ridges and grooves, ensuring accurate imaging. PEG enhances intramolecular rotation, which boosts the emission properties of the material, resulting in clearer, more detailed fingerprint imaging with better fluorescence contrast. The composite material can be used on various surfaces, making it applicable for a wide range of forensic scenarios. The optimized composite material is capable of capturing third-level fingerprint details, such as pores and ridge shapes, aiding in more precise forensic identification. The composite material is synthesized through a straightforward process, allowing for easy scalability and practical application in forensic investigations.
[0011] The conjugated thiophene is chosen as the fluorescent moiety for its lipophilicity, which enhances imaging by binding fluorescent molecules effectively to the grease phase of fingerprint grooves and ridges. This results in a higher retention capacity of fluorescent imaging. The thiophene-based emissive material exhibits superior retention capacity, which is essential for creating a reliable forensic database of LFPs.
[0012] In some embodiments, the thiophene-based emissive material exhibits green fluorescence under ultraviolet (UV) light, thereby enhancing the visual contrast between the fingerprint ridges and furrows. In some embodiments, the polyethylene glycol (PEG) acts as a viscosity modifier to improve the adherence of the thiophene-based emissive material to latent fingerprints and enabling improved coverage of fingerprint details.
[0013] In some embodiments, the thiophene-based emissive material is pH-stable ranging from 2 to 11, which enables the fluorescence composite material to maintain its fluorescent properties varying pH and concentration of the fluorescence and PEG material. In some embodiments, the fluorescence composite material further includes an additional sensor-compatible additive that enhances the stability and durability of the latent fingerprint imaging for extended periods after application.
[0014] In some embodiments, the thiophene-based emissive material is optimized to capture fingerprint details, including pores and ridge contours, through fluorescence microscopy or other optical imaging techniques. In some embodiments, the thiophene-based emissive material is synthesized by conjugating the thiophene-based emissive material and aldehyde for enhancing scalability and production. In some embodiments, the polymer matrix further includes a binder in addition to the PEG, to improve the retention capacity of the latent fingerprint image for forensic analysis.
[0015] In one aspect, a method for preparing a fluorescence composite material for latent fingerprint imaging is provided. The method includes (i) providing a thiophene-based emissive material that has aggregation induced emission enhancement (AIEE) property, (ii) conjugating the thiophene-based emissive material with aldehyde to optimize for green fluorescence emission with pH stability, (iii) providing a polymer matrix comprising polyethylene glycol (PEG) in a concentration ranging from 10% to 50%, wherein 10% to 50% of PEG is synthesized by mixing at least one of 1 gram (g), 3g, 5g, 7g, or 9g of PEG in 20 ml volume, and (iv) mixing the thiophene-based emissive material with the PEG to synthesize a fluorescence composite material, which the PEG enables the binding of the thiophene-based emissive material with grease phase of grooves and meadows of a fingerprint due to intramolecular rotation provide by the PEG for improved latent fingerprint imaging and fluorescence emission.
[0001] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:
[0003] FIG. 1 illustrates a structure of a thiophene-based fluorescence composite material and its emission images in solid/liquid state according to an embodiment herein;
[0004] FIG. 2 illustrates an aggregation induced emission enhancement (AIEE) property of a thiophene-based fluorescence composite material according to an embodiment herein;
[0005] FIG. 3 illustrates a) an exemplary latent fingerprint imaging technique and b) a third level detail of the finger print according to an embodiment herein;
[0006] FIG. 4 illustrates a) a latent fingerprint (LFP) obtained using compound 1, 2 and 3 and b) a grey scale profile obtained from Image J software according to an embodiment herein;
[0007] FIG. 5 illustrates a Scanning Electron Microscopy (SEM) image of a thiophene-based fluorescence composite material according to an embodiment herein; and
[0008] FIG. 6 is a flow diagram that illustrates a method for preparing a fluorescence composite material for latent fingerprint imaging according to an embodiment herein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0009] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0010] As mentioned, there remains a need for a fluorescence composite material for latent fingerprint imaging and a method for preparing the fluorescence composite material for latent fingerprint imaging. Various embodiments disclosed herein provide a fluorescence composite material for latent fingerprint imaging and a method for preparing the fluorescence composite material for latent fingerprint imaging. Referring now to the drawings, and more particularly to FIGS. 1 through 6, where similar reference characters denote corresponding features consistently throughout the figure's, preferred embodiments are shown.
[0016] An embodiment herein provides a fluorescence composite material for latent fingerprint imaging. The fluorescence composite material includes (i) a thiophene-based emissive material that has aggregation induced emission enhancement (AIEE) property, and the thiophene-based emissive material is conjugated with aldehyde to optimize for green fluorescence emission with pH stability, and (ii) a polymer matrix including polyethylene glycol (PEG) in a concentration ranging from 10% to 50%, wherein 10% to 50% of PEG is synthesized by mixing at least one of 1 gram (g), 3g, 5g, 7g, or 9g of PEG in 20 ml volume. The thiophene-based emissive material is mixed with the PEG to synthesize a fluorescence composite material, which the PEG enables the binding of the thiophene-based emissive material with grease phase of grooves and meadows of a fingerprint due to intramolecular rotation provide by the PEG for improved latent fingerprint imaging and fluorescence emission.
[0017] In some embodiments, the thiophene-based emissive material exhibits green fluorescence under ultraviolet (UV) light, thereby enhancing the visual contrast between the fingerprint ridges and furrows. In some embodiments, the polyethylene glycol (PEG) acts as a viscosity modifier to improve the adherence of the thiophene-based emissive material to latent fingerprints and enabling improved coverage of fingerprint details.
[0018] In some embodiments, the thiophene-based emissive material is pH-stable ranging from 2 to 11, which enables the fluorescence composite material to maintain its fluorescent properties in varying pH and concentration of the fluorescence and PEG material. In some embodiments, the fluorescence composite material further includes an additional sensor-compatible additive that enhances the stability and durability of the latent fingerprint imaging for extended periods after application.
[0019] In some embodiments, the thiophene-based emissive material is optimized to capture fingerprint details, including pores and ridge contours, through fluorescence microscopy or other optical imaging techniques. In some embodiments, the thiophene-based emissive material is synthesized by conjugating the thiophene-based emissive material and aldehyde for enhancing scalability and production. In some embodiments, the polymer matrix further includes a binder in addition to the PEG, to improve the retention capacity of the latent fingerprint image for forensic analysis.
[0020] In another embodiment, a method for preparing a fluorescence composite material for latent fingerprint imaging is provided. The method includes (i) providing a thiophene-based emissive material that has aggregation induced emission enhancement (AIEE) property, (ii) conjugating the thiophene-based emissive material with aldehyde to optimize for green fluorescence emission with pH stability, (iii) providing a polymer matrix comprising polyethylene glycol (PEG) in a concentration ranging from 10% to 50%, wherein 10% to 50% of PEG is synthesized by mixing at least one of 1 gram (g), 3g, 5g, 7g, or 9g of PEG in 20 ml volume, and (iv) mixing the thiophene-based emissive material with the PEG to synthesize a fluorescence composite material, which the PEG enables the binding of the thiophene-based emissive material with grease phase of grooves and meadows of a fingerprint due to intramolecular rotation provide by the PEG for improved latent fingerprint imaging and fluorescence emission.
[0011] FIG. 1 illustrates a structure of a thiophene-based fluorescence composite material and its emission images in solid/liquid state according to an embodiment herein. FIG. 1 shows a collection of chemical structures and their corresponding fluorescence properties. The structures labelled 1 through 5 represent various fluorescent molecules, each paired with a vial showing their fluorescence under UV light. The label 1 represents a thiophene-based structure conjugated with an aldehyde group (-CHO), emitting green fluorescence. The label 2 represents a structure with a similar thiophene backbone, emitting blue fluorescence. The label 3 represents a molecule featuring nitrogen-containing heterocycles, emitting green fluorescence. The label 4 represents another nitrogen-containing fluorescent molecule, emitting cyan light. The label 5 represents compound featuring a fused bicyclic structure with two nitrogen groups, emitting violet fluorescence. The structures 6 through 8 represent solid-state emitters, with thiophene-based backbones conjugated to a cyano group (-CN). The structure 6 represents a yellow-emitting thiophene compound. The structure 7 represents another yellow-emitting structure with a similar backbone. The structure represents an orange-emitting thiophene structure.
[0012] These compounds exhibit distinct colors of fluorescence and are likely being studied for their emission properties, potentially for applications such as latent fingerprint imaging or other fluorescent-based detection techniques. FIG. 1 illustrates the relationship between the chemical structure of each compound and its emission color under UV light.
[0021] FIG. 2 illustrates an aggregation induced emission enhancement (AIEE) property of a thiophene-based fluorescence composite material according to an embodiment herein. The fluorescence composite material includes (i) a thiophene-based emissive material that has aggregation induced emission enhancement (AIEE) property, and the thiophene-based emissive material is conjugated with aldehyde to optimize for green fluorescence emission with pH stability, and (ii) a polymer matrix including polyethylene glycol (PEG) in a concentration ranging from 10% to 50%, wherein 10% to 50% of PEG is synthesized by mixing at least one of 1 gram (g), 3g, 5g, 7g, or 9g of PEG in 20 ml volume. The thiophene-based emissive material is mixed with the PEG to synthesize a fluorescence composite material, which the PEG enables the binding of the thiophene-based emissive material with grease phase of grooves and meadows of a fingerprint due to intramolecular rotation provide by the PEG for improved latent fingerprint imaging and fluorescence emission.
[0022] To synthesize the thiophene-based emissive material using a simple procedure and characterize it using various spectroscopic techniques, including NMR, FT-IR, HRMS, UV-Vis spectroscopy, fluorescence spectroscopy, and TRPL. To assess the material's stability across a wide pH range (ranging from 2 to 11), making the thiophene-based emissive material suitable for latent fingerprint (LFP) imaging at crime scenes. The material's effectiveness is evaluated in visualizing fingerprints on different surfaces. To identify third-level fingerprint details, the synthesized thiophene-based emissive material is mixed with polyethylene glycol (PEG) in an optimized proportion and sprayed onto the fingerprint.
[0023] The polymer matrix including the PEG in the concentration ranging from 10% to 50%. The 10% to 50% of PEG is synthesized by mixing at least one of 1 gram (g), 3g, 5g, 7g, or 9g of PEG in 20 ml volume. For LFP imaging, 50% solution of PEG-6000 polymer is utilized in doubled distilled water. The preliminary studies shows that THCHO shows enhanced higher intensity at 70 % water: solvent ratio. Henceforth, for 20 ml working solution 2.2 mg of THCHO is dissolved with 14ml polymer (approximately 6g of PEG) and 6 mL solvent.
[0024] The PEG provides strong restricted intramolecular rotation, allowing the thiophene-based emissive material with aldehyde (THCHO material) to bind effectively with the fingerprint's papillary lines, resulting in clear imaging and enhanced fluorescence emission. This makes the material suitable for real-time fingerprint interpretation, enabling fast and extensive coverage when sprayed on latent fingerprints.
[0025] The thiophene-based emissive material that has aggregation induced emission enhancement (AIEE) property is synthesized using a straightforward procedure. The aggregation properties of the thiophene-based emissive material are thoroughly evaluated using various spectroscopic techniques and software tools. To enhance imaging quality and capture comprehensive details of latent fingerprints (LFP), the synthesized thiophene-based emissive material is combined with PEG. The viscosity of the fluorescence composite material ensures full coverage of the ridges and furrows of the LFP, improving the clarity and accuracy of the imaging process.
[0026] FIG. 2 includes several plots and figures showcasing the fluorescence properties and emission behaviors of thiophene-based materials, particularly in different environments and conditions. In FIG. 2, the compounds are numbered 1, 2, and 3. Compound 1: (a) illustrates fluorescence intensity vs. wavelength for a thiophene-based compound (TFCHO), showing behavior across a pH range of 2-12, indicating its pH stability, (b) illustrates fluorescence intensity vs. wavelength in different solvents (hexane, THF, toluene, chloroform, DMF, DMSO), suggesting solvent-dependent emission behavior, (c) illustrates fluorescence intensity of thiophene-based compounds mixed with PEG at different concentrations, demonstrating enhanced emission with higher PEG content, (d) illustrates f bar graph showing fluorescence intensity increasing with higher percentages of PEG and (e) illustrates test tubes containing solutions of the thiophene-based compound at different pH levels, visually illustrating fluorescence changes with pH.
[0027] Compound 2: (a) illustrates fluorescence intensity at different PEG percentages, suggesting aggregation-induced emission (AIE) behavior with increased PEG content, (b) illustrates fluorescence behavior of the compound in the pH range of 2-7 and 8-12, highlighting emission changes under different pH conditions, (c) illustrates image of test tubes showing the visible color changes with varying PEG content, and (d) illustrates test tubes showing fluorescence under UV light, demonstrating the material's fluorescence in different pH conditions.
[0028] Compound 3: (a) illustrates fluorescence intensity vs. wavelength at different water-to-solvent fractions, indicating AIE behavior in water, (b) illustrates a plot showing fluorescence intensity vs. water fraction, with a clear trend that highlights aggregation-induced effects, (c) illustrates test tubes demonstrating changes in fluorescence emission under different water fractions.
[0029] FIG. 2 demonstrates the fluorescence characteristics, pH stability, and aggregation-induced emission (AIE) behavior of the thiophene-based compounds in various solvents, PEG concentrations, and water fractions. The materials seem to show strong potential for latent fingerprint imaging due to their pH stability and enhanced fluorescence in varying pH and concentration of the fluorescence and PEG material.
[0030] The thiophene derivatives have been identified as AIEE-active materials, with their emission behavior clearly demonstrating AIEE properties in varying water-to-solvent ratios. Compounds 1, 2, and 3 exhibit vibrant green fluorescence and demonstrate broad pH stability, making them particularly well-suited for fingerprint imaging applications. Additionally, the thiophene derivatives are mixed with PEG to further evaluate their aggregation properties in a viscous medium, enhancing their potential for accurate and detailed latent fingerprint imaging.
[0031] FIG. 3 illustrates a) an exemplary latent fingerprint imaging technique and b) a third level detail of the finger print according to an embodiment herein. FIG. 3 illustrates an application of a thiophene-based compound (THCHO) for latent fingerprint imaging. The key components of the FIG. 3 include: fingerprint visualization, molecular structure, imaging process, grey scale profile and latent fingerprint imaging label. Fingerprint visualization: On the left of FIG. 3, there's a depiction of a fingerprint, likely highlighting how the THCHO material can be used for enhanced imaging of latent fingerprints. Molecular structure: At the top-center of FIG. 3, the chemical structure of THCHO is shown, representing the thiophene-based compound (i.e., fluorescence composite material) used in the process. Imaging process: A zoomed-in view (center of FIG. 3) shows different levels of fingerprint detail (1, 2, and 3) that are revealed using the THCHO material, suggesting its ability to capture minute details such as ridges and furrows.
[0032] Gray scale profile: On the right of FIG. 3, a grey scale profile is shown, which likely indicates how the imaging process captures and analyzes the intensity variations in the fingerprint for detailed analysis. Latent fingerprint imaging label: At the bottom of FIG. 3, the caption "Latent Fingerprint Imaging" indicates the primary application of the THCHO material used in the fluorescence composite material, further emphasizing its use in forensic science for visualizing latent fingerprints. FIG. 3b shows a third level detail of the finger print. A fluorescence microscope is employed to capture third-level details, such as pores and ridge shapes. FIG. 3 highlights the molecular approach to enhancing fingerprint visibility using the fluorescence composite material, suggesting that the fluorescence composite material can improve contrast and clarity in latent fingerprint imaging, particularly for detailed forensic analysis.
[0033] The synthesized thiophene derivatives are thoroughly characterized using various spectroscopic techniques, with results aligning well with theoretical predictions. Additionally, aggregation and pH stability studies are conducted to assess the materials' suitability for latent fingerprint (LFP) imaging. All green-emissive materials are tested for LFP imaging on different substrates, including steel, glass, aluminium foil, and plastic.
[0034] FIG. 4 illustrates a) a latent fingerprint (LFP) obtained using compound 1, 2 and 3 and b) a grey scale profile obtained from Image J software according to an embodiment herein. The resolution of the fingerprint image largely depends on the contrast between the major lines and furrows of the fingerprint. To evaluate this, the fluorescence emission intensity between the ridges and furrows is analyzed, and the contrast is calculated using the Michelson contrast formula. The grey-scale profile is also determined using ImageJ software to assess the intensity maxima and minima of the latent fingerprint. Similarly, the LFP is observed by using three compounds 1, 2 and 3. The result is given in the FIG. 4 with the grey scale profile of the first image and the details obtained (maximum and minimum intensity is used to calculate the contrast value, which suggests that the compound exhibits high contract value good for eliminating background fluorescence.
[0035] CM = (Imax - Imin)/ (Imax - Imin).
[0036] FIG. 5 illustrates a Scanning Electron Microscopy (SEM) image of a thiophene-based fluorescence composite material according to an embodiment herein. The thiophene-based emissive material exhibits aggregation-induced emission enhancement (AIEE) properties. The AIEE behavior is confirmed by varying the water-to-solvent ratio. Emission spectroscopy results revealed enhanced fluorescence upon aggregation, triggered by the presence of water molecules. To further improve the fluorescence emission efficiency and the material's binding affinity with LFP, the viscosity of the medium is increased by adding higher concentrations of PEG. The enhancement in fluorescence emission is evident from fluorescence (FL) spectroscopy and time-resolved photoluminescence (TRPL) decay studies. To verify the occurrence of aggregation with increasing PEG concentration, the SEM analysis is conducted. The SEM images clearly show the polymer forming a distinct wavy pattern, with the fluorescent material embedded within. FIG. 5 shows the SEM image of aggregated THCHO with PEG at magnification 500 KX (a), 4000 X (b), 5000 X (c) is the clear indication of aggregated THCHO; b1. Image at 4.0 KX exhibiting 1. Wavy patterns of PEG polymer contain 2. Pores and 3. Embedded with THCHO aggregates.
[0037] FIG. 6 is a flow diagram that illustrates a method for preparing a fluorescence composite material for latent fingerprint imaging according to an embodiment herein. At step 602, a thiophene-based emissive material that has aggregation induced emission enhancement (AIEE) property is provided. At step 604, the thiophene-based emissive material is conjugated with aldehyde to optimize for green fluorescence emission with pH stability. At step 606, a polymer matrix including polyethylene glycol (PEG) is provided. At step 608, the thiophene-based emissive material is mixed with the PEG to synthesize a fluorescence composite material, which the PEG enables the binding of the thiophene-based emissive material with grease phase of grooves and meadows of a fingerprint due to intramolecular rotation provide by the PEG for improved latent fingerprint imaging and fluorescence emission.
[0038] The thiophene-based emissive material with Aggregation-Induced Emission Enhancement (AIEE) ensures strong fluorescence emission, improving the visibility of latent fingerprints. Conjugation with aldehyde optimizes the material for green fluorescence, which is more easily detected by the human eye, enhancing the contrast and detail in fingerprint imaging. The process ensures that the resulting fluorescence composite material maintains stability across a wide pH range (ranging from 2 to 11), allowing for use in varied environmental conditions without compromising imaging performance. The inclusion of polyethylene glycol (PEG) in the polymer matrix facilitates strong binding of the thiophene-based material to the greasy phase of fingerprint ridges and grooves, ensuring effective imaging on different surfaces. The intramolecular rotation provided by PEG further enhances fluorescence emission, making the latent fingerprints more prominent and easier to analyze. The method aids in capturing intricate fingerprint details, including third-level features such as ridge structure and pores, improving forensic accuracy. The method follows a straightforward step-by-step process, making it practical for forensic applications and easy to replicate at scale.
[0039] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of appended claims.
, Claims:I/We claim:
1. A fluorescence composite material for latent fingerprint imaging, comprising:
a thiophene-based emissive material that has aggregation induced emission enhancement (AIEE) property, wherein the thiophene-based emissive material is conjugated with aldehyde to optimize for green fluorescence emission with pH stability; and
a polymer matrix comprising polyethylene glycol (PEG) in a concentration ranging from 10% to 50%, wherein 10% to 50% of PEG is synthesized by mixing at least one of 1 gram (g), 3g, 5g, 7g, or 9g of PEG in 20 ml volume, characterized in that, wherein the thiophene-based emissive material is mixed with the PEG to synthesize a fluorescence composite material, which the PEG enables the binding of the thiophene-based emissive material with grease phase of grooves and meadows of a fingerprint due to intramolecular rotation provide by the PEG for improved latent fingerprint imaging and fluorescence emission.

2. The fluorescence composite material as claimed in claim 1, wherein the thiophene-based emissive material exhibits green fluorescence under ultraviolet (UV) light, thereby enhancing the visual contrast between the fingerprint ridges and furrows.

3. The fluorescence composite material as claimed in claim 1, wherein the polyethylene glycol (PEG) acts as a viscosity modifier to improve the adherence of the thiophene-based emissive material to latent fingerprints and enabling improved coverage of fingerprint details.

4. The fluorescence composite material as claimed in claim 1, wherein the thiophene-based emissive material is pH-stable ranging from 2 to 11, which enables the fluorescence composite material to maintain its fluorescent properties in varying pH and concentration of the fluorescence and PEG material.

5. The fluorescence composite material as claimed in claim 1, wherein the fluorescence composite material further comprises an additional sensor-compatible additive that enhances the stability and durability of the latent fingerprint imaging for extended periods after application.

6. The fluorescence composite material as claimed in claim 1, wherein the thiophene-based emissive material is optimized to capture fingerprint details, including pores and ridge contours, through fluorescence microscopy or other optical imaging techniques.

7. The fluorescence composite material as claimed in claim 1, wherein the thiophene-based emissive material is synthesized by conjugating the thiophene-based emissive material and aldehyde for enhancing scalability and production.

8. The fluorescence composite material as claimed in claim 1, wherein the polymer matrix further comprises a binder in addition to the PEG, to improve the retention capacity of the latent fingerprint image for forensic analysis.

9. A method for preparing a fluorescence composite material for latent fingerprint imaging, comprising:
providing a thiophene-based emissive material that has aggregation induced emission enhancement (AIEE) property;
conjugating the thiophene-based emissive material with aldehyde to optimize for green fluorescence emission with pH stability;
providing a polymer matrix comprising polyethylene glycol (PEG) in a concentration ranging from 10% to 50%, wherein 10% to 50% of PEG is synthesized by mixing at least one of 1 gram (g), 3g, 5g, 7g, or 9g of PEG in 20 ml volume;
characterized in that,
mixing the thiophene-based emissive material with the PEG to synthesize a fluorescence composite material, which the PEG enables the binding of the thiophene-based emissive material with grease phase of grooves and meadows of a fingerprint due to intramolecular rotation provide by the PEG for improved latent fingerprint imaging and fluorescence emission.

10. The method as claimed in claim 9, wherein the thiophene-based emissive material exhibits green fluorescence under ultraviolet (UV) light, thereby enhancing the visual contrast between the fingerprint ridges and furrows.

Dated this November 06th, 2024

Arjun Karthik Bala
(IN/PA 1021)
Agent for Applicant

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