Selective quantitative detection method of fentanyl
By combining molecular imprinting and electrochemical coating technologies, a fentanyl molecularly imprinted electrochemical sensor was prepared, solving the problems of complex detection and low accuracy in existing technologies. This enabled rapid and highly selective fentanyl detection, making it suitable for drug interdiction operations.
Patent Information
- Application Number
- CN202511284398.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-09
- Publication Date
- 2025-11-28
AI Technical Summary
In the existing technology, the detection methods for fentanyl require large instruments, are complex to operate, and are not very accurate in the presence of other drug molecules, making it difficult to meet the rapid detection needs at the scene of drug seizures.
A fentanyl molecularly imprinted electrochemical sensor was prepared by combining molecular imprinting technology with electrochemical coating technology. The molecularly imprinted film was polymerized on the surface of a bare glassy carbon electrode using o-phenylenediamine as a functional monomer, and the detection was performed by differential pulse voltammetry, thus establishing a rapid and highly selective detection method.
It enables rapid and accurate detection of fentanyl in the presence of other drug molecules. The sensor is simple to prepare, has good reproducibility and selectivity, can be reused repeatedly, and has strong anti-interference capabilities.
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Figure CN121027248A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of fentanyl substance detection and identification, in particular to a selective quantitative detection method of fentanyl. BACKGROUND
[0002] Fentanyl is a synthetic opioid analgesic widely used in clinical practice. Its analgesic effect is rapid and about 100 times that of morphine. However, fentanyl is also an addictive drug with high abuse risk. Illegal fentanyl is often mixed with other drugs (such as heroin, cocaine) or disguised as prescription drugs (such as oxycodone), leading to the death of users due to uncontrolled dosage. Laboratory test results show that the purity of fentanyl tablets is increasing, with about 7 out of every 10 counterfeit drugs containing a lethal dose of fentanyl, higher than 4 out of every 10 tablets in 2021. The average purity of fentanyl powder samples is 19.2%, which has increased by 33% since 2021, ranging from almost no fentanyl (0.07%) to 81.5%.
[0003] Currently, the detection methods for fentanyl mainly include high performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), surface enhanced Raman spectroscopy (SERS), and solid phase extraction (SPE). These detection methods can achieve qualitative or quantitative detection of fentanyl, but they require large instruments and high professional requirements for operators. In addition, surface enhanced Raman spectroscopy (SERS) and fluorescence immunoassay can only be used for qualitative detection of fentanyl molecules, and have the disadvantages of low accuracy and poor anti-interference ability in concentration detection, which cannot meet the requirements of on-site detection of drug suppression. SUMMARY
[0004] In order to solve the problems in the prior art, the present application provides a selective quantitative detection method of fentanyl, which can rapidly detect fentanyl in the presence of other drug molecules, and the detection method has fast response, good selectivity and reproducibility.
[0005] To achieve the technical effects of the present application, the technical solutions of the present application are as follows: (1) Dissolve the functional monomer o-phenylenediamine in acetic acid-sodium acetate buffer solution, add fentanyl solution, and obtain fentanyl molecular imprinting pre-polymerization solution.
[0006] (2) Put the three-electrode system into the fentanyl molecular imprinting pre-polymerization solution vertically, and scan by cyclic voltammetry to prepare a fentanyl molecular imprinting film on the surface of the working electrode. After scanning, wash and dry the three-electrode system.
[0007] (3) Put the three-electrode system obtained in step (2) into methanol vertically, apply a voltage to the working electrode, and stir to elute, so that the imprinting cavities on the fentanyl molecular imprinting film are formed, i.e. a fentanyl molecular imprinting electrochemical sensor is obtained.
[0008] (4) Take a small molecule potassium ferricyanide as a probe, add a fentanyl standard solution into the potassium ferricyanide solution to obtain a fentanyl standard detection solution with different gradient concentrations, put the fentanyl molecular imprinting electrochemical sensor into the fentanyl standard detection solution vertically, incubate, and then record the current from -0.2 to 0.6 V by differential pulse voltammetry to obtain a standard curve of the fentanyl concentration and the redox peak current.
[0009] (5) Mix the to-be-detected solution with the potassium ferricyanide solution to obtain a mixed to-be-detected solution, put the fentanyl molecular imprinting electrochemical sensor into the mixed to-be-detected solution vertically, incubate for the same time as in step (4), and then record the current from -0.2 to 0.6 V by differential pulse voltammetry. The detected peak current is brought into the standard curve obtained in step (4) to obtain the fentanyl concentration in the to-be-detected solution.
[0010] Preferably, the molar ratio of the functional monomer o-phenylenediamine to the fentanyl contained in the fentanyl solution in step (1) is 1:1 to 1:1.4.
[0011] Preferably, the molar concentration of the acetic acid-sodium acetate buffer solution in step (1) is 0.1 to 0.3 mol·L -1， , and the pH is less than or equal to 6.
[0012] Preferably, the three-electrode system in step (2) comprises a working electrode, a reference electrode, and an auxiliary electrode, wherein the working electrode is a glassy carbon electrode, the reference electrode is an Ag / AgCl electrode, and the auxiliary electrode is a Pt wire electrode.
[0013] Preferably, the parameters of the cyclic voltammetry in step (2) are as follows: the number of scanning cycles is 30 to 50, the scanning range is 0 to 0.8 V, and the scanning speed is 30 to 80 mVs -1 .
[0014] Preferably, the voltage applied in step (3) is -0.2 to -0.4 V, and the elution time is 10 to 30 min.
[0015] Preferably, the incubation time in step (4) is greater than or equal to 5 min.
[0016] Preferably, the scan rate of differential pulse voltammetry in step (4) and step (5) is 50 mVs -1 .
[0017] Preferably, the volume ratio of the solution to be detected to the potassium ferricyanide solution in step (5) is 1:50.
[0018] Compared with the prior art, the present application has the following beneficial effects: (1) The present application polymerizes a layer of molecular imprinting film on the surface of a bare glassy carbon electrode by using o-phenylenediamine as a functional monomer, and the molecular imprinting film after elution by methanol and voltage has molecular imprinting pores capable of specifically adsorbing fentanyl, the combination of the functional monomer and the elution method makes the prepared sensor have the advantages of simple preparation, rapid response, good selectivity and reproducibility, and the molecular imprinting film can be repeatedly eluted and used.
[0019] (2) The present application combines molecular imprinting technology with electrochemical plating technology, optimizes the polymerization and plating conditions by preparing a polymerization solution, and uses an indirect detection method to improve the selectivity and sensitivity of fentanyl detection, and the present application uses differential pulse voltammetry (DPV) as a detection technology to establish a method capable of rapidly detecting fentanyl in the presence of other drug molecules, and the results show that the sensor has the advantages of simple preparation, rapid response, good selectivity and reproducibility, and the molecular imprinting electrode can be repeatedly used and has a long service life.
[0020] (3) The fentanyl molecular imprinting electrochemical sensor prepared by the present application has a synergistic effect with the potassium ferricyanide probe, which can improve the anti-interference and selectivity in the detection process. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 The number of electrochemical polymerization circles of the fentanyl imprinting film.
[0022] Figure 2 The DPV curves of FT-MIM / GCE (fentanyl molecular imprinting electrode) and NIM / GCE (non-imprinting electrode) before and after elution in K3[Fe(CN)6].
[0023] Figure 3 The peak current response of 1x10 -12 mol·L -1 of FT on FT-MIM / GCE under different incubation times.
[0024] Figure 4 The DPV response graph of FT with different concentrations on FT-MIM / GCE.
[0025] Figure 5 The standard working curve graph of the logarithm of different FT concentrations and the logarithm of peak current in the method of the present application. Detailed Implementation
[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, but the scope of protection of the present invention is not limited to the content described.
[0027] Example 1 A method for preparing a fentanyl molecularly imprinted electrochemical sensor, the specific steps of which are as follows: (1) Preparation of polymerization solution: Accurately weigh 0.10 mmol of the functional monomer o-phenylenediamine (o-PD) using a balance and dissolve it in 5 mL of an acetate-sodium acetate buffer solution with pH=5.2 (the molar concentration of the acetate-sodium acetate buffer solution is 0.2 mol·L⁻¹). -1 (Sonicate for 2 minutes to fully dissolve the functional monomer in the solution, then add 50 µL of a 2.68 mol·L⁻¹ solution using a pipette) -1 Fentanyl solution is subjected to sonication for 2 minutes to allow the template fentanyl to interact with the functional monomer, resulting in a fentanyl molecularly imprinted prepolymer solution.
[0028] (2) A three-electrode system was formed by using a polished glassy carbon electrode as the working electrode, an Ag / AgCl electrode as the reference electrode, and a Pt wire electrode as the auxiliary electrode. The system was vertically suspended in the fentanyl molecularly imprinted prepolymer solution and scanned using cyclic voltammetry (CV) with a scan range of 0~0.8V and a scan rate of 50mVs. -1 The number of scans is 40, from Figure 1 It can be seen that when the polymerization reaches 40 cycles, the peak current drops to 0µA, indicating that a non-conductive polymer film has been formed on the electrode surface. After the polymerization is completed, the three electrodes are rinsed clean with deionized water, and the water is absorbed by filter paper to obtain the fentanyl molecularly imprinted electrode.
[0029] (3) The three electrodes obtained in step (2) were placed in pure methanol solution, eluted at a voltage of -0.3V for 20 minutes, to obtain the fentanyl molecularly imprinted electrochemical sensor. The DPV (differential pulse voltammetry) curves of the fentanyl molecularly imprinted electrode in K3[Fe(CN)6] before and after elution are shown in the figure. Figure 2 As shown, the current remains unchanged before and after elution of the non-imprinted electrode.
[0030] Example 2 A method for preparing a fentanyl molecularly imprinted electrochemical sensor, the specific steps of which are as follows: (1) Preparation of polymerization solution: Accurately weigh 0.10 mmol of the functional monomer o-phenylenediamine (o-PD) using a balance and dissolve it in 5 mL of an acetate-sodium acetate buffer solution with pH=5.2 (the molar concentration of the acetate-sodium acetate buffer solution is 0.1 mol·L⁻¹). -1), ultrasonic 2 min to make the functional monomer fully dissolved in the solution, 38 µL of fentanyl solution with a concentration of 2.68 mol·L -1 The fentanyl solution was added, and ultrasonic 2 min was used to make the template fentanyl interact with the functional monomer, thereby obtaining a fentanyl molecular imprinting pre-polymerization solution.
[0031] (2) The polished glassy carbon electrode was used as the working electrode, the Ag / AgCl electrode was used as the reference electrode, and the Pt wire electrode was used as the auxiliary electrode to form a three-electrode system, which was vertically suspended in the fentanyl molecular imprinting pre-polymerization solution, and was scanned by cyclic voltammetry (CV), with a scanning range of 0~0.8 V, a scanning speed of 30 mVs -1 , and 15 scanning circles. When the polymerization reached 15 circles, the peak current decreased to close to 0 µA, indicating that a non-conductive polymer film had been formed on the electrode surface. After the polymerization was completed, the three electrodes were washed with deionized water, the water was absorbed with filter paper, and a fentanyl molecular imprinting electrode was obtained. Figure 1
[0032] (3) The three electrodes obtained in step (2) were placed in pure methanol solution, with an elution voltage of -0.2 V and an elution time of 30 min, thereby obtaining a fentanyl molecular imprinting electrochemical sensor.
[0033] Example 3 (1) Preparation of the polymerization solution: 0.10 mmol of the functional monomer o-phenylenediamine (o-PD) was accurately weighed by a balance and dissolved in 5 mL of an acetic acid-sodium acetate buffer solution with a pH of 5.2 (the molar concentration of the acetic acid-sodium acetate buffer solution was 0.3 mol·L -1 ), ultrasonic 2 min to make the functional monomer fully dissolved in the solution, 52 µL of fentanyl solution with a concentration of 2.68 mol·L -1 The fentanyl solution was added, and ultrasonic 2 min was used to make the template fentanyl interact with the functional monomer, thereby obtaining a fentanyl molecular imprinting pre-polymerization solution.
[0034] (2) The polished glassy carbon electrode was used as the working electrode, the Ag / AgCl electrode was used as the reference electrode, and the Pt wire electrode was used as the auxiliary electrode to form a three-electrode system, which was vertically suspended in the fentanyl molecular imprinting pre-polymerization solution, and was scanned by cyclic voltammetry (CV), with a scanning range of 0~0.8 V, a scanning speed of 35 mVs -1 , and 30 scanning circles. When the polymerization reached 30 circles, the peak current decreased to close to 0 µA, indicating that a non-conductive polymer film had been formed on the electrode surface. After the polymerization was completed, the three electrodes were washed with deionized water, the water was absorbed with filter paper, and a fentanyl molecular imprinting electrode was obtained.
[0035] (3) The three electrodes obtained in step (2) were placed in pure methanol solution, with an elution voltage of -0.4 V and an elution time of 10 min, thereby obtaining a fentanyl molecular imprinting electrochemical sensor.
[0036] Example 4 A method for preparing a fentanyl molecularly imprinted electrochemical sensor, the specific steps of which are as follows: (1) Preparation of polymerization solution: Accurately weigh 0.10 mmol of the functional monomer o-phenylenediamine (o-PD) using a balance and dissolve it in 5 mL of an acetate-sodium acetate buffer solution with pH=5.2 (the molar concentration of the acetate-sodium acetate buffer solution is 0.2 mol·L⁻¹). -1 (Sonicate for 2 minutes to fully dissolve the functional monomer in the solution, then add 50 µL of a 2.68 mol·L⁻¹ solution using a pipette) -1 Fentanyl solution was subjected to sonication for 2 minutes to allow the template fentanyl to interact with the functional monomer, resulting in a fentanyl molecularly imprinted prepolymer solution.
[0037] (2) A three-electrode system was formed by using a polished glassy carbon electrode as the working electrode, an Ag / AgCl electrode as the reference electrode, and a Pt wire electrode as the auxiliary electrode. The system was vertically suspended in the fentanyl molecularly imprinted prepolymer solution and scanned using cyclic voltammetry (CV) with a scan range of 0~0.8V and a scan rate of 80mVs. -1 The scanning circle number was 40 circles. After the polymerization was completed, the three electrodes were rinsed with deionized water and the water was absorbed by the filter paper to obtain the fentanyl molecularly imprinted electrode.
[0038] (3) The three electrodes obtained in step (2) were placed in pure methanol solution, the elution voltage was -0.3V, the elution time was 20min, and the fentanyl molecularly imprinted electrochemical sensor was obtained.
[0039] Example 5 The fentanyl molecularly imprinted electrochemical sensor prepared in Example 1 was applied to detect fentanyl in beverages. The specific steps are as follows: (1) Using potassium ferricyanide as a probe, fentanyl standard solution was added to potassium ferricyanide solution to obtain mixed detection solutions containing different concentrations of fentanyl (the final concentration of fentanyl in K3[Fe(CN)6] solution was 1.0×10⁻⁶). -12 ~1.0×10 -4 mol·L -1 The concentration of the K3[Fe(CN)6] solution was 5.0 mmol·L⁻¹. -1 It contains 0.1 mol·L -1 The fentanyl molecularly imprinted electrochemical sensor prepared in Example 1 was vertically suspended in different mixed detection solutions, such as KCl. Figure 3 As shown, the peak current decreased continuously with increasing stirring incubation time until it slowed down and stabilized after 5 minutes. Therefore, 5 minutes was defined as the optimal incubation time. After 5 minutes of incubation, the DPV current from -0.2 to 0.6 V was recorded using differential pulse voltammetry (scan rate 50 mV·s).-1 ), the peak current of potassium ferricyanide on the fentanyl molecularly imprinted electrochemical sensor decreased with the increase of fentanyl concentration, as shown in Figure 4 , the standard curve of fentanyl concentration and redox peak current was finally obtained: I(A)=-5×10 -7 c+9×10 -6 , where c was the concentration, unit: mol·L - ¹, the equation had excellent linear correlation (R²=0.99), and the detection limit of the method reached 4.0×10 - ¹² mol·L - ¹.
[0040] (2) Detection of fentanyl content in beverages: Take a brand of juice beverage sample, shake well, filter through a 0.45 μm nylon filter membrane, take 5 mL of filtrate, and prepare 0.5 mmol / L and 5 mmol / L fentanyl solutions for experiment, set 3 parallel samples for the background group; set low (0.5 mmol / L) and high (5 mmol / L) concentrations for the spiked group, and set 3 parallel samples for each concentration. Take 0.1 mL of fentanyl solution with a concentration of 0.5 mmol / L and 5 mmol / L and add it to 5.0 mL of K3[Fe(CN)6] solution (the concentration of K3[Fe(CN)6] solution is 5.0 mmol·L -1 , which contains 0.1 mol·L -1 of KCl). After vortex mixing, all samples were incubated in the fentanyl molecularly imprinted electrochemical sensor for 5 min, and the DPV current from -0.2 to 0.6 V was recorded after 5 min of incubation (the scan rate was 50 mV·s -1 ), the peak current response value was calculated by the linear equation obtained in step (5): the average spiked recovery rate of the low level group was 105.3% (RSD=2.01%), and the average spiked recovery rate of the high level group was 102.4% (RSD=0.923%), which confirmed that the fentanyl electrochemical sensor had excellent accuracy and reproducibility in the juice matrix, and could meet the quantitative detection requirements after simple pretreatment process.
[0041] The fentanyl molecularly imprinted electrochemical sensors prepared in Examples 2-4 were used to detect fentanyl in beverages in the same way, and the effect was similar to that of Example 1, but because the number of polymerization circles was different during preparation, the detection effect was slightly different.
[0042] Example 6 Selectivity and anti-interference test of fentanyl molecularly imprinted electrochemical sensor In order to study the recognition specificity of fentanyl molecularly imprinted electrochemical sensor to fentanyl, 5 mL of K3[Fe(CN)6] solution with a concentration of 5.0 mmol·L-1 K3[Fe(CN)6] (containing 0.1 mol·L -1 KCl) solution, fentanyl, morphine, methadone, heroin, cannabidiol, and ice meth were added respectively to obtain different to-be-tested solutions, so that the final concentration of fentanyl in the K3[Fe(CN)6] solution was 1.0×10 -10 mol·L -1 , and the final concentration of other substances in the K3[Fe(CN)6] solution was 1.0×10 -6 mol·L -1 The peak current of potassium ferricyanide after incubation of the fentanyl molecularly imprinted electrochemical sensor in different solutions was measured, and the result showed that the 10-fold other drug molecules of fentanyl only made the peak current of potassium ferricyanide decrease by 8% to 20% of that of fentanyl, indicating that the prepared fentanyl molecularly imprinted electrochemical sensor had good selectivity and could effectively distinguish structural analogues and common abuse drugs.
[0043] To evaluate the specific recognition ability of the fentanyl molecularly imprinted electrochemical sensor for fentanyl, 5 mL of a base solution containing 5.0 mmol·L⁻¹ K3[Fe(CN)6] and 0.1 mol·L⁻¹ KCl was added with fentanyl (FT), morphine, methadone, heroin, cannabidiol, and ice meth in turn, so that the final concentration of fentanyl in the K3[Fe(CN)6] solution was 1.0×10 -10 mol·L -1 , and the final concentration of other substances in the K3[Fe(CN)6] solution was 1.0×10 ⁻8 mol·L⁻¹. When the concentration of the interfering substance was 100 times that of fentanyl, the current response of the fentanyl molecularly imprinted electrochemical sensor to the interfering substance and fentanyl was almost unchanged compared with the current response of fentanyl alone. The experimental results showed that the molecularly imprinted electrode exhibited significant anti-interference ability for fentanyl and could detect the concentration of fentanyl in a mixed drug solution.
[0044] Example 7 Reproducibility and stability test of the fentanyl molecularly imprinted electrochemical sensor To further explore the reproducibility and stability of the fentanyl molecularly imprinted electrochemical sensor, five identical fentanyl molecularly imprinted electrochemical sensors were prepared by the method in Example 1, and these electrodes were used for 1.0×10 - 8 mol·L -1The relative standard deviation of the detection results of fentanyl was 3.7%. The same electrode was used to continuously detect the same fentanyl solution for 5 times, and the relative standard deviation of the detection results was 3.5%. The electrode could still maintain more than 90% of the initial current after being used for 5 times or stored at room temperature for one week. The above experimental data show that the fentanyl molecularly imprinted electrochemical sensor prepared by the experimental method has good repeatability, reproducibility and stability.
Claims
1. A selective and quantitative method for the detection of fentanyl, characterized in that: The method comprises the following steps: (1) dissolving functional monomer o-phenylenediamine in acetic acid-sodium acetate buffer solution, adding fentanyl solution to obtain fentanyl molecular imprinting pre-polymerization solution; (2) vertically suspending a three-electrode system in the fentanyl molecular imprinting pre-polymerization solution, scanning by cyclic voltammetry to prepare a fentanyl molecular imprinting membrane on the surface of a working electrode, and cleaning and drying the three-electrode system after scanning; (3) vertically suspending the three-electrode system obtained in step (2) in methanol, applying a voltage to the working electrode and stirring to elute, so that imprinting cavities on the fentanyl molecular imprinting membrane are formed, i.e. a fentanyl molecular imprinting electrochemical sensor is obtained; (4) using potassium ferricyanide as a probe, adding fentanyl standard solution to the potassium ferricyanide solution to obtain fentanyl standard detection solution with different gradients, vertically suspending the fentanyl molecular imprinting electrochemical sensor in the fentanyl standard detection solution for incubation, recording the current from -0.2 to 0.6 V by differential pulse voltammetry after incubation, and obtaining a standard curve of fentanyl concentration and redox peak current; (5) mixing the to-be-detected solution with the potassium ferricyanide solution to obtain a mixed to-be-detected solution, vertically suspending the fentanyl molecular imprinting electrochemical sensor in the mixed to-be-detected solution for incubation, wherein the incubation time is the same as that in step (4), recording the current from -0.2 to 0.6 V by differential pulse voltammetry after incubation, and obtaining the fentanyl concentration in the to-be-detected solution by bringing the detected peak current into the standard curve obtained in step (4).
2. The method for selective and quantitative detection of fentanyl according to claim 1, characterized in that: In step (1), the molar ratio of the functional monomer o-phenylenediamine to fentanyl contained in the fentanyl solution is 1:1-1:1.
4.
3. The method of selective quantification of fentanyl according to claim 1, wherein: The molar concentration of the acetic acid-sodium acetate buffer solution in step (1) is 0.1-0.3 mol / L -1 , pH≤6.
4. The method of selective quantification of fentanyl according to claim 1, wherein: In step (2), the three-electrode system comprises a working electrode, a reference electrode and an auxiliary electrode, wherein the working electrode is a glassy carbon electrode, the reference electrode is an Ag / AgCl electrode, and the auxiliary electrode is a Pt wire electrode.
5. The method of selective quantification of fentanyl according to claim 1, wherein: The parameters of the cyclic voltammetry in step (2) are as follows: the scanning number is 30-50, the scanning range is 0-0.8 V, and the scanning speed is 30-80 mVs -1 .
6. The method of selective quantification of fentanyl according to claim 1, wherein: In step (3), the applied voltage is -0.2 to -0.4 V, and the elution time is 10-30 min.
7. The method of selective quantification of fentanyl according to claim 1, wherein: In step (4), the incubation time is ≥5 min.
8. The method of selective quantification of fentanyl according to claim 1, wherein: The scan rate of differential pulse voltammetry in step (4) and step (5) is 50 mVs -1 .