Trisemitting mofs and smartphone-based tryptamine detection method

Abstract

The application discloses a tryptamine detection method based on triple emission MOFs and a smart phone. A rare earth metal organic framework (AP-Eu) is used as a luminescent matrix, and a fluorescent guest molecule fluorescein-5-isothiocyanate (FITC) is post-modified to obtain a ratio fluorescent material with triple emission characteristics. Competitive absorption of ligands and tryptamine, pH response of FITC and hydrogen bonding are used to realize fluorescence signal regulation, and then high-sensitivity and high-selectivity fluorescence recognition of tryptamine is realized. The method is further applied to quantitative detection of tryptamine in beer samples, visualization detection of foam and on-site rapid detection assisted by a mobile phone APP. The application provides a safe and efficient tryptamine detection and fluorescence sensing method, and significantly improves detection accuracy and on-site applicability.

Description

Technical Field

[0001] This invention belongs to the field of fluorescence sensing and intelligent detection technology, specifically relating to a fluorescence detection method, detection device and its application based on metal-organic framework materials. Background Technology

[0002] Tryptophan is an important class of biogenic amines, widely found in fermented foods, beverages, and biological samples. Changes in its content can serve as an important indicator for evaluating food quality and related physiological states. Therefore, establishing rapid and accurate methods for tryingptophan detection is of great significance.

[0003] Currently, tryptamine detection mainly relies on techniques such as high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS), and fluorescence sensing. While HPLC and LC-MS offer high sensitivity and accuracy, they generally suffer from drawbacks such as expensive equipment, complex sample pretreatment, long detection cycles, and difficulty in on-site testing. Fluorescence sensing offers advantages such as ease of operation, rapid response, and lower cost; however, most existing fluorescence sensing systems employ single-emission or dual-emission signal modes, making them susceptible to interference from environmental factors and sample matrices, thus affecting the accuracy and stability of the detection results.

[0004] Furthermore, existing fluorescence sensing systems based on metal-organic frameworks still suffer from insufficient selectivity, limited anti-interference capabilities, and low applicability in the field of tryptamine detection. Meanwhile, most existing detection methods rely on laboratory instruments for signal acquisition and data analysis, lacking portable detection methods integrated with smart terminals, making it difficult to meet the needs for rapid on-site detection and real-time analysis.

[0005] Therefore, it is necessary to develop a tryptamine detection method and system that is highly selective, highly stable, and suitable for rapid on-site analysis. Summary of the Invention

[0006] This invention provides a tryptamine detection material, detection method, and detection system based on triple emission ratio fluorescence and smart terminal analysis.

[0007] The detection material is a rare earth metal-organic framework material FITC@AP-Eu covalently modified with fluorescein-5-isothiocyanate (FITC); AP-Eu is synthesized from Eu(NO3)3·6H2O, 2-aminoterephthalic acid and 1,10-phenanthroline, and FITC is covalently linked to the AP-Eu structure.

[0008] Furthermore, the FITC@AP-Eu simultaneously generates three characteristic fluorescence emission signals at 435 nm, 535 nm, and 614 nm under ultraviolet light excitation, corresponding to the ligand emission signal, the FITC emission signal, and the Eu emission signal, respectively.3+ Characteristic emission signal; after tryptamine interacts with the fluorescent probe, it causes a synergistic change in fluorescence intensity at three emission centers, and quantitative detection of tryptamine is achieved by constructing a triple emission factor.

[0009] Furthermore, the present invention provides a foam-loaded portable fluorescence sensor, wherein the FITC@AP-Eu is loaded onto the surface of a porous foam carrier to construct a visual detection platform.

[0010] Application of the above-mentioned FITC@AP-Eu triple emission ratio fluorescence detection material in quantitative detection of tryptamine;

[0011] The above-mentioned foam-loaded portable fluorescence sensor is used in the rapid on-site detection of tryptamine.

[0012] Furthermore, this invention provides a rapid on-site detection method for tryptamine based on a smart terminal. By acquiring images from a fluorescence sensor and extracting color feature parameters, a color fusion index Con_RGB is constructed to achieve quantitative analysis of tryptamine concentration.

[0013] Furthermore, the intelligent terminal includes an image acquisition module, a region selection module, a color feature extraction module, a target object recognition module, a concentration calculation module, and a result output module, enabling rapid on-site detection of tryptophan samples.

[0014] The FITC@AP-Eu triple emission ratiometric fluorescent probe designed in this invention introduces FITC into the AP-Eu system through covalent modification, constructing ligand emission, FITC emission, and Eu emission. 3+ A triple emission system with coordinated emission response. The interaction between tryptophan and the probe induces coordinated changes in fluorescence signals from multiple emission centers. Through joint analysis of the triple emission ratio signal and color fusion index, high sensitivity, high selectivity, and visual detection of tryptophan are achieved. Further integration with intelligent terminal analysis technology enables the digitization, portability, and rapid on-site analysis of the detection results.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) A triple emission ratio detection system was constructed using three emission centers at 435 nm, 535 nm and 614 nm, which significantly improved the stability and anti-interference ability of the detection results;

[0017] (2) Constructing a triple emission factor I tef This enables accurate quantitative analysis of tryptophan concentration;

[0018] (3) A foam-loaded fluorescence sensor is used to achieve rapid and visual detection of tryptamine;

[0019] (4) Introduce a smart terminal analysis method based on the color fusion index Con_RGB to realize the digitization and quantification of detection results;

[0020] (5) It realizes the organic combination of laboratory fluorescence detection and on-site intelligent terminal detection, and is suitable for the rapid detection of tryptamine in food samples, especially beer samples. Attached Figure Description

[0021] Figure 1 The X-ray diffraction (XRD) pattern of the FITC@AP-Eu triple emission ratio fluorescent probe in Example 1 of this invention (comparing the simulated AP-Eu pattern with the actual pattern to verify the phase purity of the material).

[0022] Figure 2 The images show scanning electron microscope (SEM) images and elemental distribution maps of the FITC@AP-Eu triple emission ratio fluorescent probe in Example 1 of this invention (the left image shows the morphology of AP-Eu, and the right image shows the morphology of FITC@AP-Eu, proving that FITC is uniformly modified and does not change the morphology of AP-Eu).

[0023] Figure 3 The fluorescence titration spectrum of the FITC@AP-Eu triple emission ratio fluorescent probe in Example 1 of this invention is shown.

[0024] Figure 4 The UV spectrum curves of FITC at different pH values ​​in Example 1 of this invention are shown.

[0025] Figure 5 This is the linear relationship graph of fluorescence titration of the FITC@AP-Eu triple emission ratio fluorescent probe in Example 1 of the present invention and the linear fitting curve of tryptophan concentration, R. 2 =0.9992.

[0026] Figure 6 This is a bar chart verifying the selectivity of the FITC@AP-Eu triple emission ratio fluorescent probe in Example 1 of the present invention (compare the effects of tryptamine and interfering substances such as glucose and urea on the fluorescence intensity ratio to prove high selectivity).

[0027] Figure 7 This is a bar chart showing the seven-day stability of the FITC@AP-Eu triple emission ratio fluorescent probe in Example 1 of the present invention.

[0028] Figure 8 shows the fluorescence lifetime decay curve of the FITC@AP-Eu triple emission ratio fluorescent probe in Example 1 of the present invention (comparing Eu before and after tryptamine treatment). 3+ The lifetime changes of FITC and atpt ligands were used to verify the hydrogen bonding mechanism.

[0029] Figure 9To present the CIE 1931 chromaticity diagram for colorimetric response.

[0030] Figure 10 The diagram shows the theoretical study of tryptophan-induced fluorescence enhancement (a) the distribution of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the original ester-state FITC-aptamer (FITC-atpt); b) the distribution of HOMO and LUMO of the open-ring state FITC-aptamer, indicating the existence of intramolecular charge transfer from FITC to the aptamer (atpt).

[0031] Figure 11 The diagram shows the frontier molecular orbital distribution (HOMO and LUMO) of the FITC-atpt / tryptamine complex.

[0032] Figure 12 This is a visualization of the tryptamine concentration gradient detection based on the FITC@AP-Eu paper-based sensor.

[0033] Figure 13 These are actual photos of the Android software we developed.

[0034] Figure 14 This represents the linear correlation between the weighted index con_rgb and tryptophan concentration.

[0035] Figure 15 A flowchart for target object identification and quantitative detection of tryptophan in smart terminals.

[0036] Figure 16 The sampling flowchart for the Android software RGB developed for colorimetric quantification. Detailed Implementation

[0037] The following further describes the content of this invention, but it should not be construed as limiting the invention. Any modifications or substitutions made to the methods, steps, or conditions of this invention without departing from the spirit and essence of this invention are within the scope of this invention.

[0038] The specific process is as follows:

[0039] 1. AP-Eu synthesis

[0040] Europium nitrate hexahydrate (Eu(NO3)3·6H2O), 2-aminoterephthalic acid (C8H7NO4), and 1,10-phenanthroline (C 12 H8N2) is dissolved in deionized water at a certain molar ratio, and alkali is added to adjust the pH. The mixture is then subjected to a hydrothermal reaction at 120~200 ℃ for 6~24 hours. After washing and drying, AP-Eu is obtained.

[0041] 2. FITC@AP-Eu synthesis

[0042] AP-Eu and FITC were dispersed in N,N-dimethylformamide at a certain mass ratio and stirred at 25-50°C for 12-48 hours under light-protected conditions. After centrifugation, washing, and vacuum drying, FITC@AP-Eu was obtained.

[0043] 3. Triple emission characteristics and tryptamine fluorescence detection

[0044] The FITC@AP-Eu prepared using the above method was used as a fluorescent probe for fluorescence performance testing. Under ultraviolet light excitation, FITC@AP-Eu simultaneously generated three characteristic fluorescence emission signals at 435 nm, 535 nm, and 614 nm, corresponding to ligand emission, FITC emission, and Eu emission, respectively. 3+ Characteristic emission indicates that the constructed probe possesses triple emission fluorescence properties. Adding tryptophan to the probe system resulted in a synergistic change in the three emission signals. A triple emission factor I was constructed based on the fluorescence intensities at 435 nm, 535 nm, and 614 nm. tef =((I 435 +I 535 ) / 2) / I 614 It is used to characterize changes in tryptophan concentration and to achieve quantitative detection of tryptophan.

[0045] 4. Detection of tryptophan in beer samples

[0046] Take 1 mL of beer and add tryptophan standard solution (1~6 mM) to prepare a spiked sample; add probe dispersion and detect according to the above method.

[0047] 5. Fabrication and Detection of Foam-Loaded Portable Sensors

[0048] FITC@AP-Eu was loaded onto the surface of a foam carrier with a three-dimensional interconnected pore structure. The foam carrier can adsorb and enrich tryptamine in the sample, improve the contact efficiency between tryptamine and the fluorescent probe, and realize the visual detection of tryptamine.

[0049] 6. Mobile APP detection and target branch determination

[0050] Develop supporting intelligent terminal detection software. Acquire fluorescence images of the foam sensor under 365–377 nm ultraviolet light irradiation, extract the R, G, and B color parameters of the detection area, and calculate the color fusion index according to the formula Con_RGB=aR+bG+cB, where a, b, and c are pre-determined weighting coefficients. Input Con_RGB into a pre-established tryptamine concentration calibration model for concentration calculation, and complete quantitative detection by calling the corresponding analysis model through the target analyte identification module.

[0051] Furthermore, to verify the response mechanism, detection performance, and smart terminal application effect of the FITC@AP-Eu probe of this invention, relevant tests were conducted on the materials. The results show that the pH response behavior of FITC is as follows: Figure 4 As shown; the selectivity and stability of the probe for tryptamine are respectively as follows: Figure 6 and Figure 7 As shown in Figure 8; the change in fluorescence lifetime of the probe before and after tryptophan treatment is shown in Figure 9; the change in luminescence color and the visualization response are shown in Figure 10. Figure 9 As shown; theoretical calculation results are as follows Figure 10 and Figure 11 As shown; the correlation between the color blending index Con_RGB and tryptophan concentration is as follows. Figure 14 As shown; the intelligent terminal target object identification and quantitative detection process is as follows: Figure 15 As shown; the RGB color parameter acquisition and processing process is as follows: Figure 16 As shown in the figure. The above results collectively demonstrate that the triple emission ratio fluorescence detection system constructed in this invention has good detection performance and potential for field application.

[0052] Example 1

[0053] 1. AP-Eu synthesis

[0054] Europium nitrate hexahydrate (Eu(NO3)3·6H2O, 0.072 g), 2-aminoterephthalic acid (C8H7NO4, 0.032 g), and 1,10-phenanthroline (C8H7NO4, 0.032 g) were subjected to ultrasonic treatment. 12 H8N2 (0.027 g) was dissolved in 5 mL of deionized water to obtain a clear solution; 0.42 mL of 0.65 M NaOH aqueous solution was added dropwise to the solution, and the mixture was stirred at room temperature for 30 min; the mixture was transferred to a 25 mL Teflon-lined reactor and reacted at 120 ℃ for 24 h; after cooling, the mixture was centrifuged at 8000 rpm for 15 min, the solid was collected, washed three times each with deionized water and ethanol, and dried under vacuum at 60 ℃ for 8 h to obtain AP-Eu.

[0055] 2. FITC@AP-Eu synthesis

[0056] AP-Eu (0.1 g) and FITC (0.1 g) were added to 20 mL of N,N-dimethylformamide and stirred at room temperature for 1 h. After wrapping with aluminum foil, the mixture was stirred in a water bath at 25 ℃ for 48 h. After centrifugation at 10000 rpm for 20 min, the mixture was washed with N,N-dimethylformamide until the supernatant showed no fluorescence. The mixture was then vacuum dried at 50 ℃ for 12 h to obtain FITC@AP-Eu. The XRD pattern and SEM morphology of the obtained material are shown below. Figure 1 and Figure 2 As shown, this indicates that the material was successfully prepared.

[0057] 3. Triple emission characteristics and tryptamine fluorescence detection

[0058] A 0.2 mg / mL FITC@AP-Eu probe dispersion was prepared, and 1 mL was added to a quartz cuvette. Fluorescence spectra were recorded under 377 nm excitation. The structure of the obtained FITC@AP-Eu was characterized. The results showed that the material maintained a good crystal structure and morphology and exhibited stable triple emission characteristics. Different concentrations of tryptophan standard solutions (0.1–5 mM) were added to the probe system before detection. The results are as follows: Figure 3 As shown, with increasing tryptamine concentration, emission at 435 nm and 535 nm increases, while emission at 614 nm decreases. According to Formula I... tef =((I 435 +I 535 ) / 2) / I 614 Construct a triple emission factor. The results are as follows: Figure 5 As shown, I tef It showed a good linear relationship with tryptophan concentration, with a linear correlation coefficient R. 2 =0.9992, detection limit is 0.018 mM.

[0059] 4. Detection of tryptophan in beer samples

[0060] Take 1 mL of beer and add tryptophan standard solution (1~6 mM) to prepare a spiked sample; add 0.1 mL of probe dispersion and detect the spiked recovery rate of 97.3%~109.2%, RSD<4.7%.

[0061] 5. Fabrication and Detection of Foam-Loaded Portable Sensors

[0062] Take 50 μL of FITC@AP-Eu ethanol suspension (4 mg·mL⁻¹) and add it dropwise onto the surface of melamine foam (7 mm in diameter and 1 mm in thickness), then allow it to dry at room temperature. Add 5 μL of tryptamine solutions of different concentrations (0–10 mM) to the foam and observe the fluorescence color change under 365 nm UV light. The results are as follows: Figure 12 As shown, the fluorescent color on the foam surface gradually changes from red to blue as the tryptamine concentration increases, enabling naked-eye recognition.

[0063] 6. Mobile APP detection and target branch determination

[0064] Develop a dedicated mobile app with an interface like this Figure 13As shown, this system is used for fluorescence image acquisition, RGB color parameter extraction, target analyte identification, and concentration calculation. During detection, fluorescence images of the foam sensor are acquired under ultraviolet light irradiation. The R, G, and B values ​​of the detection area are extracted, and the color fusion index is calculated using the formula Con_RGB=aR+bG+cB. The app determines the target analyte based on a pre-established target analyte identification model. When it identifies tryptamine, it calls the corresponding concentration calibration model to calculate and output the detection result. The detection results show that the deviation between the predicted concentration and the actual concentration is less than 5%.

[0065] Example 2

[0066] 1. AP-Eu synthesis

[0067] Europium nitrate hexahydrate (Eu(NO3)3·6H2O, 0.072 g), 2-aminoterephthalic acid (C8H7NO4, 0.032 g), and 1,10-phenanthroline (C8H7NO4, 0.032 g) were subjected to ultrasonic treatment. 12 H8N2 (0.027 g) was dissolved in 5 mL of deionized water to obtain a clear solution; 0.42 mL of 0.65 M NaOH aqueous solution was added dropwise to the solution, and the mixture was stirred at room temperature for 30 min; the mixture was transferred to a 25 mL Teflon-lined reactor and reacted at 160 ℃ for 12 h; after cooling, the mixture was centrifuged at 8000 rpm for 15 min, the solid was collected, washed three times each with deionized water and ethanol, and dried under vacuum at 60 ℃ for 8 h to obtain AP-Eu.

[0068] 2. FITC@AP-Eu synthesis

[0069] AP-Eu (0.1 g) and FITC (0.1 g) were added to 20 mL of N,N-dimethylformamide and stirred at room temperature for 1 h. After being wrapped in aluminum foil, the mixture was stirred in a water bath at 35 ℃ for 24 h. After centrifugation at 10,000 rpm for 20 min, the mixture was washed with N,N-dimethylformamide until the supernatant showed no fluorescence. The mixture was then dried under vacuum at 50 ℃ for 12 h to obtain FITC@AP-Eu.

[0070] 3. Triple emission characteristics and tryptamine fluorescence detection

[0071] A 0.2 mg / mL FITC@AP-Eu probe dispersion was prepared, and 1 mL was added to a quartz cuvette. Fluorescence spectra were recorded under 377 nm excitation. The structure of the obtained FITC@AP-Eu was characterized. The results showed that the material maintained a good crystal structure and morphology and exhibited stable triple emission characteristics. Different concentrations of tryptamine standard solutions (0.1–5 mM) were added to the probe system for detection. With increasing tryptamine concentration, emission at 435 nm and 535 nm increased, while emission at 614 nm decreased. According to Formula I... tef =((I435 +I 535 ) / 2) / I 614 Construct a triple emission factor. tef It showed a good linear relationship with tryptophan concentration, with a linear correlation coefficient R. 2 =0.9992, detection limit is 0.018 mM.

[0072] 4. Detection of tryptophan in beer samples

[0073] Take 1 mL of beer and add tryptophan standard solution (1~6 mM) to prepare a spiked sample; add 0.1 mL of probe dispersion and detect the spiked recovery rate of 97.3%~109.2%, RSD<4.7%.

[0074] 5. Fabrication and Detection of Foam-Loaded Portable Sensors

[0075] 50 μL of FITC@AP-Eu ethanol suspension (4 mg·mL⁻¹) was added dropwise to the surface of melamine foam (7 mm in diameter, 1 mm thick) and allowed to dry at room temperature. 5 μL of tryptamine solutions of different concentrations (0–10 mM) were then added to the foam, and the fluorescence color change was observed under 365 nm UV light. The fluorescence color on the foam surface gradually changed from red to blue with increasing tryptamine concentration, achieving naked-eye recognition.

[0076] 6. Mobile APP detection and target branch determination

[0077] A dedicated mobile app was developed for fluorescence image acquisition, RGB color parameter extraction, target analyte identification, and concentration calculation. During detection, fluorescence images of the foam sensor are acquired under ultraviolet light irradiation. The R, G, and B values ​​of the detection area are extracted, and the color fusion index is calculated using the formula Con_RGB=aR+bG+cB. The app uses a pre-established target analyte identification model for determination. When tryptophan is identified, the corresponding concentration calibration model is invoked to calculate and output the detection result. Detection results show that the deviation between the predicted and actual concentrations is less than 4.5%.

[0078] Example 3

[0079] 1. AP-Eu synthesis

[0080] Europium nitrate hexahydrate (Eu(NO3)3·6H2O, 0.072 g), 2-aminoterephthalic acid (C8H7NO4, 0.032 g), and 1,10-phenanthroline (C8H7NO4, 0.032 g) were subjected to ultrasonic treatment. 12H8N2 (0.027 g) was dissolved in 5 mL of deionized water to obtain a clear solution; 0.42 mL of 0.65 M NaOH aqueous solution was added dropwise to the solution, and the mixture was stirred at room temperature for 30 min; the mixture was transferred to a 25 mL Teflon-lined reactor and reacted at 200 ℃ for 6 h; after cooling, the mixture was centrifuged at 8000 rpm for 15 min, the solid was collected, washed three times each with deionized water and ethanol, and dried under vacuum at 60 ℃ for 8 h to obtain AP-Eu.

[0081] 2. FITC@AP-Eu synthesis

[0082] AP-Eu (0.1 g) and FITC (0.1 g) were added to 20 mL of N,N-dimethylformamide and stirred at room temperature for 1 h. After being wrapped in aluminum foil, the mixture was stirred in a water bath at 50 ℃ for 12 h. After centrifugation at 10,000 rpm for 20 min, the mixture was washed with N,N-dimethylformamide until the supernatant showed no fluorescence. The mixture was then dried under vacuum at 50 ℃ for 12 h to obtain FITC@AP-Eu.

[0083] 3. Triple emission characteristics and tryptamine fluorescence detection

[0084] A 0.2 mg / mL FITC@AP-Eu probe dispersion was prepared, and 1 mL was added to a quartz cuvette. Fluorescence spectra were recorded under 377 nm excitation. The structure of the obtained FITC@AP-Eu was characterized. The results showed that the material maintained a good crystal structure and morphology and exhibited stable triple emission characteristics. Different concentrations of tryptamine standard solutions (0.1–5 mM) were added to the probe system for detection. With increasing tryptamine concentration, emission at 435 nm and 535 nm increased, while emission at 614 nm decreased. According to Formula I... tef =((I 435 +I 535 ) / 2) / I 614 Construct a triple emission factor. tef It showed a good linear relationship with tryptophan concentration, with a linear correlation coefficient R. 2 =0.9992, detection limit is 0.018 mM.

[0085] 4. Detection of tryptophan in beer samples

[0086] Take 1 mL of beer and add tryptophan standard solution (1~6 mM) to prepare a spiked sample; add 0.1 mL of probe dispersion and detect the spiked recovery rate of 96.8%~109.2%, RSD<0.048%.

[0087] 5. Fabrication and Detection of Foam-Loaded Portable Sensors

[0088] 50 μL of FITC@AP-Eu ethanol suspension (4 mg·mL⁻¹) was added dropwise to the surface of melamine foam (7 mm in diameter, 1 mm thick) and allowed to dry at room temperature. 5 μL of tryptamine solutions of different concentrations (0–10 mM) were then added to the foam, and the fluorescence color change was observed under 365 nm UV light. The fluorescence color on the foam surface gradually changed from red to blue with increasing tryptamine concentration, achieving naked-eye recognition.

[0089] 6. Mobile APP detection and target branch determination

[0090] A dedicated mobile app was developed for fluorescence image acquisition, RGB color parameter extraction, target analyte identification, and concentration calculation. During detection, fluorescence images of the foam sensor are acquired under ultraviolet light irradiation. The R, G, and B values ​​of the detection area are extracted, and the color fusion index is calculated using the formula Con_RGB=aR+bG+cB. The app determines the target analyte based on a pre-established target analyte identification model. When tryptophan is identified, the corresponding concentration calibration model is invoked to calculate and output the detection result. Detection results show that the deviation between the predicted and actual concentrations is less than 4.5%.

[0091] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for detecting tryptamine based on triple emission ratio fluorescence, characterized in that, Rare earth metal-organic frameworks covalently modified with fluorescein-5-isothiocyanate were used as fluorescent probes. The sample to be tested was brought into contact with the fluorescent probe, and the fluorescence intensity I at 435 nm, 535 nm, and 614 nm was recorded under ultraviolet light excitation. 435 I 535 I 614 ; Based on triple emission factor I tef =((I 435 +I 535 ) / 2) / I 614 The calibration model between the test sample and the tryptamine concentration is used to calculate the tryptamine concentration in the sample.

2. The method for detecting tryptamine using triple emission ratio fluorescence as described in claim 1, characterized in that, The excitation wavelength of the ultraviolet light is 365~377 nm; the sample to be tested is a beer sample.

3. A foam-loaded portable fluorescence sensor for on-site visual detection of tryptamine, characterized in that, The sensor includes a melamine foam substrate and a FITC@AP-Eu fluorescent material loaded on the surface of the melamine foam substrate; The FITC@AP-Eu material is composed of a rare earth metal-organic framework AP-Eu and fluorescein-5-isothiocyanate connected by thiourea covalent bonds.

4. A rapid on-site detection method for tryptophan based on a smart terminal, characterized in that, Includes the following steps: (1) Obtain the fluorescence image corresponding to the sample to be tested using the fluorescence sensor as described in claim 3; (2) Extract the R, G, and B color parameters of the fluorescence image detection area; (3) Con_RGB is constructed based on the color feature fusion model. The Con_RGB is calculated according to the formula: Con_RGB=aR+bG+cB; (4) Input the Con_RGB into the pre-established tryptamine concentration calibration model to calculate the tryptamine concentration in the sample to be tested; (5) Output the detection results.

5. The method as described in claim 4, characterized in that, The intelligent terminal identifies the target analyte before performing concentration calculation; it determines the category of the target analyte based on the sensor material information, fluorescence color feature information, and a preset recognition model; when the target analyte is determined to be tryptamine, the corresponding Con_RGB-concentration calibration model is invoked; when the target analyte is determined to be non-tryptamine, the corresponding target analyte detection model is invoked.

6. The method as described in claim 5, characterized in that, The target object branch determination is achieved using a preset recognition model; the preset recognition model takes RGB color features, color ratio features, or color fusion features as input and the target detection object category as output.

7. The method as described in claim 4, characterized in that, The weighting coefficients a, b, and c are obtained through the following steps: collecting the R, G, and B color parameters corresponding to multiple known concentrations of tryptamine standard samples; A multiple linear regression model was established with tryptamine concentration as the dependent variable and R, G, and B color parameters as independent variables. The weight coefficients a, b, and c were obtained by solving the model using the least squares method.

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