A method for revealing biological evidence traces

Abstract

This invention relates to a method for revealing biological evidence traces. The method involves treating the object with a biofluorescent revealing reagent, allowing it to react at room temperature, and then revealing the evidence traces under instrument irradiation. The biofluorescent revealing reagent, by weight percentage, comprises: 0.01%–0.7% indane, 0.005%–0.02% ZnCl₂, 1%–6% ethyl acetate, 1%–6% methanol, 5%–20% ethanol, and 80%–92% CFC; wherein the CFC is 1,1,2-trichlorotrifluoroethane. Using this biofluorescent revealing reagent can shorten the required reaction time and enhance the final fluorescence revealing effect, while allowing the biological evidence traces to be revealed in permeable objects at room temperature. Furthermore, the biofluorescent revealing reagent of this invention can reduce discomfort caused by irritating odors during operation, exhibiting higher safety and stability.

Description

[0001] This invention is a divisional application of a Chinese patent application filed on March 23, 2023, with application number 2023102875083, entitled "A biofluorescence display reagent and a method and application for displaying biological evidence traces". Technical Field

[0002] This invention relates to a method for revealing biological evidence traces. Background Technology

[0003] In the field of criminal evidence investigation, it is necessary to discover and obtain criminal evidence left by suspects in order to construct a chain of evidence for the facts of the crime and lay a legal evidentiary foundation for punishing crimes. This evidence includes fingerprint evidence, palm print evidence, and trace evidence that can reflect DNA characteristics.

[0004] In existing technologies, inventors have proposed using indanedione for fingerprint development. Currently, mainstream bio-development reagents require a reaction time of 15-30 minutes, the specific duration depending on the environment. Furthermore, the rapid evaporation of the reagent can cause discomfort to operators due to its irritating odor. For example, Chinese patent CN104605860B describes a fluorescent developing reagent prepared using indanedione, glacial acetic acid, ethyl acetate, and petroleum ether. This reagent is sprayed onto a permeable object, which is then dried in an environment with relative humidity less than 40% and a temperature of 50-120°C. The dried object is then irradiated with a laser with a wavelength of 532 nm and a broad-spectrum half-width of less than 1 nm, controlling the surface illumination to exceed 300,000 lux. Under a 540 nm cutoff filter, biological evidence traces on the permeable object can be developed, effectively extracting fingerprints from bricks, sticks, fabrics, and leather. However, during use, it was found that evidence treated using this method needed to be heated to a certain temperature and left to stand for more than 15 minutes. Furthermore, the fluorescent developing agent used had a strong, irritating acidic odor, which could easily cause discomfort to operators. In contrast, Chinese patent CN106802292B describes a biofluorescent developing agent with the following raw material formula: indanedione, ethyl acetate, glycerin, pure alcohol, and petroleum ether. The indanedione reacts with sweat amino acids. This method uses a biofluorescent developing agent without a noticeable acidic odor, thus avoiding discomfort for operators. However, during use, ambient temperature and humidity significantly affect the effectiveness of the developing agent. It still requires heating to a certain temperature and drying for 10-15 minutes. If the ambient temperature is low and the humidity is high, the reaction time required for the developing agent is longer, making it impossible to effectively shorten the reaction time and reduce the irritating odor of the biofluorescent developing agent while simultaneously enhancing the fluorescence effect. Summary of the Invention

[0005] Based on the problems existing in the prior art, the purpose of this invention is to provide a biofluorescence display reagent and a method and application for displaying biological evidence traces. The biofluorescence display reagent has a short reaction time and high safety.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a biological fluorescence display reagent, which, by weight percentage, comprises: 0.01% to 0.7% indanedione, 0.005% to 0.02% ZnCl2, 1% to 6% ethyl acetate, 1% to 6% methanol, 5% to 20% ethanol and 80% to 92% CFC.

[0007] Furthermore, the biofluorescence display reagent comprises, by weight percentage: 0.01%–0.4% indanedione, 0.006%–0.009% ZnCl2, 1%–4% ethyl acetate, 1%–3% methanol, 5%–15% ethanol, and 83%–91% CFC.

[0008] Preferably, the volume ratio of ethanol to CFC is 1:2.5 to 9.

[0009] Furthermore, the volume ratio of ethanol to CFC is 1:3 to 8.5.

[0010] Furthermore, the volume ratio of ethanol to CFC is 1:3.5 to 8.5, for example 3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5.

[0011] Furthermore, the volume ratio of ethanol to CFC is 1:3.5 to 4.0.

[0012] Preferably, the CFC (chlorofluorocarbon) is 1,1,2-trichlorotrifluoroethane.

[0013] Preferably, the volume ratio of ethyl acetate to methanol is 1:0.3 to 3.

[0014] Further, the volume ratio of ethyl acetate to methanol is 1:0.4 to 2.5, for example: 1:0.4, 1:0.7, 1:1, 1:1.3, 1:1.5, 1:1.8, 1:2.1, 1:2.4, 1:2.5.

[0015] Furthermore, the volume ratio of ethyl acetate to methanol is 1:2 to 2.5.

[0016] Preferably, the preparation method of the biofluorescence display reagent is as follows: the biofluorescence display reagent is obtained by directly mixing the indanedione, ZnCl2, ethyl acetate, methanol, ethanol and CFC.

[0017] A second aspect of the present invention provides a method for displaying biological evidence traces, wherein the object is treated with the aforementioned biofluorescent display reagent, reacted at room temperature, and then the evidence traces are displayed under instrument irradiation.

[0018] Preferably, the room temperature conditions are a temperature of 5–25°C and a relative humidity of <80%.

[0019] Furthermore, the room temperature conditions are a temperature of 5–20°C and a relative humidity of <78%.

[0020] Furthermore, the room temperature conditions are a temperature of 8–15°C and a relative humidity of <76%.

[0021] Preferably, the reaction time is controlled to be 3 to 9 minutes.

[0022] Specifically, the reaction time can be adjusted according to the specific object. For example, when the object is a brick, the reaction time is controlled to be 5 to 9 minutes; when the object is a piece of textile fabric, the reaction time is controlled to be 3 to 6 minutes; and when the object is white paper, the reaction time is controlled to be 1 to 2 minutes.

[0023] Preferably, the object is treated by soaking, spraying, or dripping with the biofluorescence display reagent.

[0024] Preferably, the biological evidence includes a handprint, which can be a fingerprint or palm print.

[0025] According to a specific and preferred embodiment, the development method specifically involves: soaking, spraying, or dripping the object with the biofluorescent development reagent, reacting it for 3 to 9 minutes at a temperature of 5–25°C and a relative humidity of <80%, then irradiating the sample with green light of 532 nm for examination, controlling the surface to form an illuminance of 300,000 lux, and developing the physical evidence traces by photographic means under a 540 nm filter.

[0026] A third aspect of the present invention provides the application of a biofluorescence display reagent in displaying biological evidence traces on a subject.

[0027] Preferably, the object is one of a permeable object with a rough surface or a semi-permeable object with a rough surface.

[0028] Further, the object includes one of the following: bricks, textile fabric, logs, white walls, white paper, kraft paper, toilet paper, invoices, leather, and coated rebar; more preferably, one of bricks, textile fabric, and white paper; even more preferably, bricks and textile fabric.

[0029] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0030] In this invention, ninhydrin is used as the main material, and a mixed solution of ethyl acetate and methanol is selected as the solvent for ninhydrin. Appropriate amounts of zinc chloride and CFCs are added to shorten the required reaction time of the prepared biofluorescence display reagent. Furthermore, it allows permeable or semi-permeable objects to react and reveal biological evidence traces at room temperature. In addition, the biofluorescence display reagent of this invention reduces discomfort caused by irritating odors during operation, exhibiting higher safety and stability. Attached Figure Description

[0031] Figure 1 Fingerprint images of the biofluorescent display reagents used in Example 1 and Comparative Example 1 on bricks;

[0032] Figure 2 Fingerprint images of the biofluorescent display reagents used in Example 1 and Comparative Example 1 on textile fabric segments;

[0033] Figure 3 Fingerprint images of the biofluorescent display reagents used in Example 1 and Comparative Example 2 on bricks;

[0034] Figure 4 Fingerprint images of the biofluorescent display reagents used in Example 1 and Comparative Example 2 on textile fabric segments;

[0035] Figure 5 Fingerprint images of the biofluorescent display reagents used in Example 1 and Comparative Example 3 on bricks;

[0036] Figure 6 Fingerprint images of the biofluorescent display reagents used in Example 1 and Comparative Example 3 on textile fabric segments;

[0037] Figure 7 Fingerprint images of the biofluorescent display reagents used in Example 1 and Comparative Example 4 on bricks;

[0038] Figure 8 Fingerprint images of the biofluorescent display reagents used in Example 1 and Comparative Example 4 on textile fabric segments;

[0039] Figure 9 Fingerprint images of the biofluorescent display reagents used in Example 2 and Comparative Example 5 on bricks;

[0040] Figure 10 Fingerprint images of the biofluorescent display reagents used in Example 2 and Comparative Example 5 on textile fabric segments;

[0041] Figure 11Fingerprint images of the biofluorescent display reagents used in Example 2 and Comparative Example 6 on bricks;

[0042] Figure 12 Fingerprint images of the biofluorescent display reagents used in Example 2 and Comparative Example 6 on textile fabric segments;

[0043] Figure 13 Fingerprint images of the biofluorescent display reagents used in Example 2 and Comparative Example 7 on bricks;

[0044] Figure 14 Fingerprint images of the biofluorescent display reagents used in Example 2 and Comparative Example 7 on textile fabric segments;

[0045] Figure 15 Fingerprint images of the biofluorescent display reagents used in Example 2 and Comparative Example 8 on bricks;

[0046] Figure 16 Fingerprint images of the biofluorescent display reagents used in Example 2 and Comparative Example 8 on textile fabric segments.

[0047] Attached image description: Figure 1-16 In the figure, the left image shows the biofluorescence display effect in the embodiment, and the right image shows the biofluorescence display effect in the comparative example. Detailed Implementation

[0048] All features disclosed in this invention, or steps in all methods or processes disclosed, may be combined in any way, except for mutually exclusive features or steps.

[0049] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The following will further explain and illustrate this technical solution, its implementation process, and its principles.

[0050] This invention utilizes ninhydrin as the main material for the visualization of biological traces from permeable or semi-permeable objects. It employs the reaction of ninhydrin with amino acids in sweat to generate an intermediate product that can produce fluorescence under specific conditions (reaction principle as shown in the formula below). Simultaneously, a small amount of ZnCl2 is added to the system, which synergistically reacts with methanol, ethyl acetate, ethanol, and CFCs to form a novel biofluorescent display reagent. This biofluorescent display reagent exhibits a short reaction time with permeable or semi-permeable objects, is minimally affected by environmental factors such as temperature and humidity, and demonstrates high safety and stability, reducing discomfort caused to operators by irritating odors during use.

[0051]

[0052] Furthermore, in the biofluorescence display reagent of the present invention, the mass percentage of ZnCl2 is 0.005-0.02%, preferably 0.006-0.009%. Zinc ions will also produce fluorescence under laser irradiation, and in tandanedione will work synergistically to enhance the display effect.

[0053] Furthermore, the biofluorescence display reagent of this invention includes methanol, which is mixed with ethyl acetate to act as a solvent for ninhydrin and zinc chloride. The volume ratio of ethyl acetate to methanol is strictly controlled within the range of 1:0.3 to 3. Ninhydrin and zinc chloride have good solubility in the system, and methanol is more volatile than pure alcohol, which can improve the overall volatility of the reagent solution. At the same time, a small amount of methanol replaces part of the ethyl acetate, reducing the amount of ethyl acetate used, thereby reducing the irritating odor during the reagent volatilization process and further reducing the discomfort of the staff.

[0054] Furthermore, in this invention, CFC is selected as the diluent, specifically 1,1,2-trichlorotrifluoroethane, avoiding the use of flammable petroleum ether. 1,1,2-trichlorotrifluoroethane has higher volatility and stability than petroleum ether, and a weaker odor, which is beneficial for further improving the volatility of the reagent. Simultaneously, the volume ratio of ethanol to CFC is strictly controlled at 1:2.5–9, preferably 1:3.5–8.5; more preferably 1:3.5–4.0. This allows the reagent to better shorten the reaction time required by ethyl acetate, methanol, and ZnCl2, accelerating the development of biological evidence traces on the surface of permeable or semi-permeable objects, improving the safety of the bio-development reagent, and further reducing the content of irritating odorous materials, thus reducing the irritation to workers during reagent volatilization. In addition, CFC is more stable than petroleum ether, improving the stability of the biofluorescence development reagent.

[0055] The present invention will be further described below with reference to embodiments. However, the present invention is not limited to the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to different requirements of specific applications, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in the various embodiments of the present invention can be combined with each other as long as they do not conflict with each other.

[0056] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; and the experimental materials used, unless otherwise specified, were purchased from conventional biochemical reagent manufacturers.

[0057] Example 1

[0058] In this embodiment, a quantitative dripping method is used to treat the sample (specifically, a brick or piece of textile fabric with fingerprints) with 1 mL of biofluorescent developing reagent. The sample is left to stand at room temperature (8°C, 76% humidity) to allow it to react naturally. The sample is then examined by irradiating it with green light at a wavelength of 532 nm, and the surface is controlled to form an illuminance of 300,000 lux. The fingerprint is then obtained by photographing under a 540 nm filter.

[0059] The biological fluorescence display reagent, by weight percentage, includes: 0.02 g indanedione, 0.01 g ZnCl2, 2 mL ethyl acetate, 5 mL methanol, 10 mL ethanol, and an appropriate amount of 1,1,2-trichlorotrifluoroethane (approximately 83 mL) to a final volume of 100 mL.

[0060] Comparative Example 1

[0061] This comparative example is basically the same as Example 1, except that the biofluorescence display reagent, by weight percentage, includes: 0.02g ninhydrin, 2mL ethyl acetate, 10mL ethanol, and an appropriate amount of petroleum ether (about 88mL) to a final volume of 100mL.

[0062] The samples were treated with the reagents in Example 1 and Comparative Example 1, respectively. The fingerprint images obtained after the fingerprints were fully displayed are shown below. Figure 1 and 2 As shown (samples: bricks, textile fabric fragments).

[0063] To compare the development effects, the experiment employed a controlled variable method. Under identical conditions and on similar objects, the same person pressed two fingerprints. One fingerprint was treated with the experimental reagents (reagents from Examples 1 and 2), while the other was treated with the control reagents (reagents from Comparative Examples 1-8). The samples were examined every 30 seconds by irradiating them with green light at a wavelength of 532 nm. The onset and complete development times of the two reagents were observed and recorded, and the rate of improvement in the onset development time was calculated. During fingerprinting, both hands were left untreated to ensure consistent contact time and pressure. Common samples were uniformly selected for the experiment: bricks and pieces of textile fabric.

[0064] Improvement rate / % = (Time to onset of reaction of control reagent - Time to onset of reaction of experimental reagent) / Time to onset of reaction of control reagent × 100%

[0065] The test results are shown in Table 1.

[0066] Table 1. Results of display time tests for Example 1 and Comparative Example 1

[0067]

[0068] This experiment mainly compares the differences in development effect between the reagents in Example 1 and the reagents in Comparative Example 1. The experimental data shows that the fingerprints in Example 1 started to develop and developed completely faster than those in Comparative Example 1. When the fingerprints in Example 1 started to develop on the brick and the textile fabric, the fingerprints in Comparative Example 1 did not start to develop at all.

[0069] Comparative Example 2

[0070] This comparative example is basically the same as Example 1, except that the biological fluorescence display reagent, by weight percentage, includes: 0.02g ninhydrin, 0.01g ZnCl2, 2mL ethyl acetate, 5mL methanol, 10mL ethanol, and an appropriate amount of petroleum ether (about 83mL) to a final volume of 100mL.

[0071] The samples were treated with the reagents from Example 1 and Comparative Example 2, respectively. The fingerprint images obtained after the fingerprints were fully displayed are shown below. Figure 3 and 4 The test results are shown in Table 2 (samples: bricks, textile fabric pieces).

[0072] Table 2. Results of display time tests for Example 1 and Comparative Example 2

[0073]

[0074] This group of experiments mainly studied the effects of CFCs and petroleum ethers on the development effect. The experimental data showed that the fingerprints in Example 1 developed faster at both the initial and complete development speeds than those in Comparative Example 2. On bricks and textile fabrics, the fingerprints in Example 1 began to develop on both surfaces, while the fingerprints in Comparative Example 2 did not begin to develop at all.

[0075] Comparative Example 3

[0076] This comparative example is basically the same as Example 1, except that the biological fluorescence display reagent, by weight percentage, includes: 0.02g ninhydrin, 2mL ethyl acetate, 5mL methanol, 10mL ethanol, and an appropriate amount of 1,1,2-trichlorotrifluoroethane (about 83mL) to be diluted to 100mL.

[0077] The samples were treated with the reagents from Example 1 and Comparative Example 3, respectively. The fingerprint images obtained after the fingerprints were fully displayed are shown below. Figure 5 and 6 As shown in Table 3, the test results are as follows (samples: bricks, textile fabric pieces).

[0078] Table 3. Results of display time tests for Example 1 and Comparative Example 3

[0079]

[0080] This group of experiments mainly studied the effect of ZnCl2 on the development effect. The experimental data showed that the fingerprints in Example 1 developed faster at both the initial and complete development speeds than those in Comparative Example 3. On bricks and textile fabrics, the fingerprints in Example 1 began to develop on the bricks and textile fabrics, while the fingerprints in Comparative Example 3 had not yet begun to develop.

[0081] Comparative Example 4

[0082] This comparative example is basically the same as Example 1, except that the biological fluorescence display reagent, by weight percentage, includes: 0.02g ninhydrin, 0.01g ZnCl2, 2mL ethyl acetate, 5mL methanol, 45mL ethanol, and an appropriate amount of 1,1,2-trichlorotrifluoroethane (about 48mL) to be diluted to 100mL.

[0083] The samples were treated with the reagents from Example 1 and Comparative Example 4, respectively. The fingerprint images obtained after the fingerprints were fully displayed are shown below. Figure 7 and 8 The test results are shown in Table 4 (samples: bricks, textile fabric pieces).

[0084] Table 4. Results of display time tests for Example 1 and Comparative Example 4

[0085]

[0086] This group of experiments mainly studied the effect of the ratio of ethanol to CFC on the development effect. Specifically, compared to Example 1, Comparative Example 4 kept other components of the experimental reagents unchanged, but increased the ethanol content to 45 mL and decreased the CFC content to approximately 48 mL. The experimental data showed that the fingerprint initiation and complete development speeds in Example 1 were both faster than those in Comparative Example 4. The reagents in Comparative Example 4 were significantly less volatile than those in Example 1; that is, when the fingerprints began to develop, the reagents in Comparative Example 4 had not yet completely evaporated and had not yet begun to develop.

[0087] Example 2

[0088] This embodiment is basically the same as Example 1, except that: the biological fluorescence display reagent, by weight percentage, includes: 0.5g ninhydrin, 0.01g ZnCl2, 5mL ethyl acetate, 2mL methanol, 20mL ethanol, and an appropriate amount of 1,1,2-trichlorotrifluoroethane (about 73mL) to be diluted to 100mL.

[0089] Comparative Example 5

[0090] This comparative example is basically the same as Example 2, except that the biofluorescence display reagent, by weight percentage, includes: 0.5g ninhydrin, 5mL ethyl acetate, 10mL ethanol, and an appropriate amount of petroleum ether (about 85mL) to a final volume of 100mL.

[0091] The samples were treated with the reagents from Example 2 and Comparative Example 5, respectively. The fingerprint images obtained after the fingerprints were fully displayed are shown below. Figure 9 and 10 The test results are shown in Table 5 (samples: bricks, textile fabric pieces).

[0092] Table 5. Results of display time tests for Example 2 and Comparative Example 5

[0093]

[0094] This group of experiments mainly compared the differences in the development effects of the reagents in Example 2 and Comparative Example 5, specifically the effects of adding ZnCl2, methanol, ethanol, and replacing petroleum ether with CFC on fingerprint development on the samples in Example 2. The experimental data showed that the initial and complete development speeds of fingerprints in Example 2 were both faster than those in Comparative Example 5. On bricks and textile fabrics, the fingerprints in Example 2 began to develop while the fingerprints in Comparative Example 5 had not yet begun to develop.

[0095] Comparative Example 6

[0096] This comparative example is basically the same as Example 2, except that the biofluorescence display reagent, by weight percentage, includes: 0.5g ninhydrin, 0.01g ZnCl2, 5mL ethyl acetate, 2mL methanol, 20mL ethanol, and an appropriate amount of petroleum ether (about 73mL) to a final volume of 100mL.

[0097] The samples were treated with the reagents in Example 2 and the reagent 6 in the comparative example, respectively. The fingerprint images obtained after the fingerprints were fully displayed are shown below. Figure 11 and 12 The test results are shown in Table 6 (samples: bricks, textile fabric pieces).

[0098] Table 6. Results of display time tests for Example 2 and Comparative Example 6

[0099]

[0100] This group of experiments mainly studied the effects of CFC and petroleum ether on the development effect. Specifically, compared to Example 2, Comparative Example 6 did not change other components of the experimental reagents, only replacing CFC with petroleum ether. The experimental data showed that the fingerprints in Example 2 developed at a faster rate in both initial and complete development than those in Comparative Example 6. On both bricks and textile fabrics, the fingerprints in Example 2 did not begin to develop at the same time as the fingerprints in Comparative Example 6.

[0101] Comparative Example 7

[0102] This comparative example is basically the same as Example 2, except that the biological fluorescence display reagent, by weight percentage, includes: 0.5g ninhydrin, 5mL ethyl acetate, 2mL methanol, 20mL ethanol, and an appropriate amount of 1,1,2-trichlorotrifluoroethane (about 73mL) to be diluted to 100mL.

[0103] The samples were treated with the reagents from Example 2 and Comparative Example 7, respectively. The fingerprint images obtained after the fingerprints were fully displayed are shown below. Figure 13 and 14 The test results are shown in Table 7 (samples: bricks, textile fabric pieces).

[0104] Table 7. Results of display time tests for Example 2 and Comparative Example 7

[0105]

[0106] This group of experiments mainly studied the effect of ZnCl2 on the development effect. Specifically, compared with Example 2, Comparative Example 7 did not change other components of the experimental reagents, only removing ZnCl2. The experimental data showed that the fingerprints in Example 2 started to develop and the fingerprints in Comparative Example 7 developed faster than those in Comparative Example 7. On bricks and textile fabrics, the fingerprints in Example 2 started to develop before the fingerprints in Comparative Example 7 had even started to develop.

[0107] Comparative Example 8

[0108] This comparative example is basically the same as Example 2, except that the biological fluorescence display reagent, by weight percentage, includes: 0.5g ninhydrin, 0.01g ZnCl2, 5mL ethyl acetate, 2mL methanol, 45mL ethanol, and an appropriate amount of 1,1,2-trichlorotrifluoroethane (about 48mL) to be diluted to 100mL.

[0109] The samples were treated with the reagents from Example 2 and Comparative Example 8, respectively. The fingerprint images obtained after the fingerprints were fully displayed are shown below. Figure 15 and 16 The test results are shown in Table 8 (samples: bricks, textile fabric pieces).

[0110] Table 8. Results of display time tests for Example 2 and Comparative Example 8

[0111]

[0112] This group of experiments mainly studied the effect of the ratio of ethanol to CFC (1,1,2-trichlorotrifluoroethane) on the development effect. Specifically, compared to Example 2, Comparative Example 8 did not change other components of the experimental reagents, but increased the ethanol content to 45 mL and decreased the CFC content to approximately 48 mL. The experimental data showed that the initial and complete fingerprint development speeds in Example 2 were both faster than in Comparative Example 8. On bricks and textile fabrics, the volatility of the reagent in Comparative Example 8 was significantly lower than that in Example 2. When fingerprints in Example 2 began to develop, the reagent in Comparative Example 8 had not yet completely evaporated and had not yet begun to develop.

[0113] Comparative observations were conducted between experimental reagent 1 and control reagents 1-4, and experimental reagent 2 and control reagents 5-8. The results showed that CFCs were superior to petroleum ether as a solvent in the indanedione developing reagent. Adding trace amounts of ZnCl2 to the reagent accelerated the developing speed and improved the developing effect. Controlling the ratio of ethanol to CFC increased the overall volatility of the reagent, thereby improving the developing speed, especially on bricks and textiles. In summary, the fingerprint developing speeds of experimental reagents 1 and 2 were faster than those of the control reagents. Furthermore, the fingerprint developing effects of experimental reagents 1 and 2 were comparable to or even better than those of the control reagents.

[0114] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for revealing biological evidence traces, characterized in that: The object is treated with a biofluorescent developing reagent, reacted at room temperature, and then the physical evidence is revealed under instrument irradiation. The biofluorescent developing reagent, by weight percentage, comprises: 0.01%–0.7% indanedione, 0.005%–0.02% ZnCl2, 1%–6% ethyl acetate, 1%–6% methanol, 5%–20% ethanol, and 80%–92% CFC; wherein the CFC is 1,1,2-trichlorotrifluoroethane; and the room temperature condition is 5–25°C.

2. The method for revealing biological evidence traces according to claim 1, characterized in that: The room temperature condition is 5–20°C.

3. The method for revealing biological evidence traces according to claim 2, characterized in that: The room temperature condition is 8–15°C.

4. The method for revealing biological evidence traces according to claim 1, characterized in that: The reaction is carried out under conditions of relative humidity <80%.

5. The method for revealing biological evidence traces according to claim 1, characterized in that: The reaction time is controlled to be 3 to 9 minutes.

6. The method for revealing biological evidence traces according to claim 5, characterized in that: When the object is a brick, the reaction time is controlled to be 5 to 9 minutes.

7. The method for revealing biological evidence traces according to claim 5, characterized in that: When the object is a piece of textile fabric, the reaction time is controlled to be 3 to 6 minutes.

8. The method for revealing biological evidence traces according to claim 1, characterized in that: The object is treated by soaking, spraying, or dripping with the aforementioned biofluorescence display reagent.

9. The method for revealing biological evidence traces according to claim 1, characterized in that: The specific method of development is as follows: the object is soaked, sprayed or dripped with the biofluorescent development reagent and reacted for 3 to 9 minutes at a temperature of 5 to 25°C. Then, the sample is irradiated with green light with a wavelength of 532 nm for examination, and the surface is controlled to form an illuminance of 300,000 lux. The physical evidence traces are then developed by photographic means under a 540 nm filter.

10. The method for revealing biological evidence traces according to claim 1, characterized in that: The biological evidence includes handprints, which are fingerprints or palm prints.

Images