Method for selectively detecting metronidazole by using chiral carbon quantum dot fluorescent probe
By using chiral carbon quantum dot fluorescent probe to detect metronidazole, the problems of complex detection, high cost and difficulty in on-site detection in the prior art are solved, and the low-cost, high selectivity and rapid metronidazole detection effect is achieved.
Patent Information
- Application Number
- CN202510314609.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2025-05-09
AI Technical Summary
The prior art has problems such as complex sample preprocessing, high detection cost, large and expensive instruments and professional operators when detecting metronidazole, and it is difficult to achieve rapid on-site inspection.
Chiral carbon quantum dot fluorescent probe was used to generate biomass sugarcane molasses-based chiral carbon quantum dots (Ch-CQDs) through ultrasonic treatment and drying reaction, and the fluorescence response characteristics were used for selective detection of metronidazole.
It realizes convenient, low-cost and highly selective metronidazole detection, with a detection limit of up to 0.66 μmol/L and a linear correlation coefficient of up to 0.98494, which is suitable for the fields of medicine, food safety and environmental monitoring.
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Figure CN119959202A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of nanomaterial sensing research, and in particular to a method for selectively detecting metronidazole using a biomass chiral carbon quantum dot fluorescent probe. Background Art
[0002] In the field of medical testing, metronidazole is a widely used antibacterial drug, and its accurate detection is of great significance. In medical treatment, it can ensure the quality of treatment, guide the rational use of drugs and avoid adverse reactions; in the field of food safety, it can protect the health of consumers, maintain market order and prevent problematic foods from entering the market; in environmental monitoring, it helps to assess pollution and guide governance.
[0003] Currently, the methods for detecting metronidazole mainly include high-performance liquid chromatography, liquid chromatography-mass spectrometry, etc. However, these traditional methods also have some limitations. The sample pretreatment of high-performance liquid chromatography is complicated, involving extraction, purification and other steps, and the operation is cumbersome and time-consuming [Tuamsomboon P, Charumanee S, Junmahasathien T, et al. Effect of Vehicles and Irrigation Solutions and Methods on Removal of DoubleAntibiotic Paste from Root Canals: Insights from High-performance LiquidChromatography Analysis [J]. Journal of Endodontics, 2024, 50(9): 1307-13.]. In addition, it relies on expensive instruments and professionals, and the detection cost is high. Although liquid chromatography-mass spectrometry has high sensitivity and selectivity, the instrumentation is more expensive, the maintenance cost is high, and the professional requirements for operators are extremely high, which is not conducive to its widespread application [Su Y, Lu J, Liu J, et al. Optimization, validation, and application ofa liquid chromatography-tandem mass spectrometry method for the determinationof 47 banned drug and related chemical residues in livestock urine usinggraphitized carboxyl multi-walled carbon nanotubes-based QuEChERS extraction[J]. Journal of Chromatography A, 2024, 1721: 464858. Chen M, Xu H, Yuan W,et al. Identification of the major photodegradant in metronidazole by LC-PDA-MS and its reveal in compendial methods [J]. Scientific Reports, 2022, 12(1):11665.].In addition, these methods are difficult to achieve rapid on-site testing and are unable to meet the needs of primary medical institutions and drug production sites for rapid quality monitoring of metronidazole to obtain content information.
[0004] As a new type of fluorescent nanomaterial, carbon quantum dots have shown great potential in the field of analytical detection. Among them, chiral carbon quantum dots provide a new way to achieve selective detection due to their unique chiral structure and excellent optical properties. The use of chiral carbon quantum dot fluorescent probes to detect metronidazole is expected to overcome the shortcomings of traditional detection methods. On the one hand, fluorescence detection methods are usually easy to operate and have a rapid response, which can greatly simplify the detection process and reduce the detection time. On the other hand, chiral carbon quantum dot fluorescent probes achieve selective detection of metronidazole, avoiding interference from other similar structures, thereby improving the accuracy of detection. This new detection method has the advantages of relatively low cost, high sensitivity, simple operation, reliable method and low detection limit. It also provides a more convenient, efficient and low-cost solution for the detection of metronidazole, and has broad application prospects in many fields such as pharmaceutical quality control and clinical testing. Summary of the invention
[0005] The purpose of the present invention is to provide a method for selectively detecting metronidazole using a chiral carbon quantum dot fluorescent probe.
[0006] The specific steps of the method for selectively detecting metronidazole using a chiral carbon quantum dot fluorescent probe are as follows:
[0007] (1) Dissolve 0.1-0.5 g chiral glutamic acid and 0.5-5.0 g sugarcane molasses in 20-80 mL ultrapure water and mix well.
[0008] (2) The solution obtained in step (1) is ultrasonicated in an ultrasonic machine, and then the ultrasonicated solution is transferred to a polytetrafluoroethylene liner, and finally loaded into a stainless steel shell of a reactor and reacted in a constant temperature forced air drying oven at 120-220°C for 6-18 hours. After the reaction is completed and cooled to room temperature, the reaction is filtered and centrifuged to obtain a chiral carbon quantum dots (Ch-CQDs) stock solution based on biomass sugarcane molasses;
[0009] (3) Take 100 μL of the Ch-CQDs stock solution obtained in step (2), add 0-200 μL of the test solution containing metronidazole (MNZ) (0.01 mol / L), dilute the solution to 10 mL with ultrapure water, shake well and place 4 mL of the solution in a cuvette. After standing for 2 minutes, use a VARIAN fluorescence spectrophotometer to select a test voltage of 550 V, an excitation and emission slit of 5 nm, and an excitation wavelength of 335-365 The fluorescence spectrum test was carried out under the condition of 100 nm to obtain the fluorescence emission spectrum data in response to different MNZ concentrations; the intensity of the Ch-CQDs emission peak (i.e., peak value) was substituted into (F0-F) / F0 (F0 represents the initial fluorescence intensity of Ch-CQDs, and F represents the fluorescence intensity after adding MNZ), and a linear relationship (F0-F) / F0=b+aX (b is the intercept, a is the slope, and X is the concentration of the MNZ solution to be tested) was established with the concentration of the MNZ solution to be tested to calculate the detection limit (LOD) and obtain the linear correlation coefficient (R 2 ); At the same time, the MNZ content is calculated by the fluorescence intensity results;
[0010] Preferably, the metronidazole drug has a purity of 99%;
[0011] Preferably, the chiral glutamate drug has a purity of 98%;
[0012] The prepared Ch-CQDs have the following characteristics:
[0013] (1) Ch-CQDs are chiral carbon quantum dots;
[0014] (2) Ch-CQDs have the best excitation at 350 nm and the best emission at 435 nm;
[0015] (3) The chiral carbon quantum dots are spherical in shape and have a uniform particle size distribution. Under optimal conditions, the particle size is between 2.25 nm and 4.55 nm, the average particle size is 3.30 nm, and the interplanar spacing is 0.22 nm.
[0016] The present invention can detect metronidazole conveniently, at low cost and with high selectivity, with a minimum detection limit (LOD) of 0.66 μmol / L and a linear correlation coefficient (R 2 ) can reach 0.98494, and the detection linear range is 1.0×10 -5 mol / L~2.0×10 -4 mol / L.
[0017] The solution to be tested includes but is not limited to the prepared solution, domestic wastewater, tap water, and factory sewage. Domestic wastewater refers to wastewater discharged from daily life in residences, schools, hospitals, shops, public places, and toilets of industrial enterprises; tap water refers to water produced by a water treatment plant after purification and disinfection and meets the corresponding standards for use in people's life and production; factory sewage refers to water discharged from chemical plants after treatment.
[0018] The beneficial effects of the present invention are:
[0019] The biomass carbon quantum dot fluorescent probe obtained by the invention is obtained by means of chiral molecule modification and has a selective response to MNZ.
[0020] The detection method of the present invention is simple and rapid, has high sensitivity and low detection limit, does not require large-scale instruments and equipment, and greatly saves time and energy. It can be rapidly promoted in the fields of nanomedicine, bioimaging, biosensing and chemical sensing, and promote the rapid development of related fields. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is the CD spectrum of Ch-CQDs in Example 1.
[0022] Figure 2 TEM image (a) and fluorescence excitation emission spectrum comparison diagram (b) of L-CQDs in Example 1.
[0023] Figure 3 This is a comparison chart of the fluorescence excitation emission spectra of D-CQDs in Example 2.
[0024] Figure 4 (a) is the fluorescence response diagram of L-CQDs to 9 different antibiotics and 7 amino acids in Example 3, and (b) is the fluorescence response diagram of D-CQDs to 9 different antibiotics and 7 amino acids in Example 4.
[0025] Figure 5 1 is a graph showing the fluorescence emission spectra of Ch-CQDs quenched by different concentrations of MNZ in Example 3 (a), and 2 is a graph showing the linear relationship between the fluorescence quenching degree of Ch-CQDs and the MNZ concentration in Example 4 (b).
[0026] Figure 6 1. The fluorescence emission spectra of D-CQDs quenched by MNZ at different concentrations in Example 4 (a), and the linear relationship between the fluorescence quenching degree of D-CQDs and the MNZ concentration in Example 4 (b). DETAILED DESCRIPTION
[0027] Embodiment 1:
[0028] (1) Dissolve 0.3 g L-glutamic acid and 1.2 g sugarcane molasses in 30 mL ultrapure water and mix well.
[0029] (2) The solution obtained in step (1) was placed in a centrifuge tube, ultrasonicated in an ultrasonic machine, and then placed in a polytetrafluoroethylene liner, and finally placed in a reactor and reacted in a constant temperature blast drying oven at 200 °C for 12 h. After the reaction was completed and cooled to room temperature, the solution was filtered and centrifuged to obtain a chiral carbon quantum dot (L-CQDs) stock solution based on biomass sugarcane molasses. The CD spectrum of the obtained solution is shown in Figure 1 , an upward chiral signal appears in the figure, which indicates the specific chiral properties of L-CQDs (L-type). Figure 2 (a), the L-CQDs morphology is spherical, the particle size distribution is uniform, the average particle size is between 2.25 nm and 4.55 nm, the average particle size is 3.30 nm, and the interplanar spacing is 0.22 nm. The fluorescence excitation emission spectrum comparison is shown in Figure 2 (b) When the excitation wavelength is 350 nm, the fluorescence intensity of L-CQDs is maximum at 435 nm.
[0030] Embodiment 2:
[0031] (1) Dissolve 0.3 g of D-glutamic acid and 1.2 g of sugarcane molasses in 30 mL of ultrapure water and mix well.
[0032] (2) The solution obtained in step (1) was placed in a centrifuge tube, ultrasonicated in an ultrasonic machine, and then placed in a polytetrafluoroethylene liner, and finally placed in a reactor and reacted in a constant temperature blast drying oven at 200 °C for 12 h. After the reaction was completed and cooled to room temperature, the solution was filtered and centrifuged to obtain a stock solution of chiral carbon quantum dots (D-CQDs) based on biomass sugarcane molasses. The CD spectrum of the obtained solution is shown in Figure 1 , a downward chiral signal appears in the figure, which shows the specific chiral properties of L-CQDs (D type). The fluorescence excitation emission spectrum comparison is shown in Figure 3 , when the excitation wavelength is 350 nm, the fluorescence intensity of L-CQDs is the maximum at 435 nm.
[0033] Embodiment 3:
[0034] Take 100 μL of the L-CQDs stock solution obtained in step Example 1, add 0-200 μL of the test solution containing metronidazole (MNZ) (0.01 mol / L); dilute the solution to 10 mL with ultrapure water, shake well and place 4 mL of the solution in a cuvette, let it stand for 2 minutes, and use a VARIAN fluorescence spectrophotometer to select a test voltage of 550 V, an excitation and emission slit of 5 nm, and an excitation wavelength of 335-365 nm for fluorescence spectrum testing to obtain fluorescence emission spectrum data in response to different MNZ concentrations (see Figure 5 (a)); Substitute the peak value of the Ch-CQDs emission peak into (F0-F) / F0 (F0 represents the initial fluorescence intensity of L-CQDs, and F represents the fluorescence intensity after adding MNZ), and establish a linear relationship with the concentration of the added MNZ solution (F0-F) / F0=b+aX (b is the intercept, a is the slope, and X is the concentration of the MNZ solution to be tested) to calculate the detection limit (LOD) and obtain the linear correlation coefficient (R 2 ); At the same time, the MNZ content is calculated by the fluorescence intensity results;
[0035] The results showed that the L-CQDs can detect MNZ with high selectivity (see Figure 4 (a)), the corresponding detection linear range is 1.0×10 -5 mol / L~2.0×10 -4 mol / L (see Figure 5 (b) ), with a limit of detection (LOD) of 0.67 nmol / L and a corresponding linear correlation coefficient of 0.97567.
[0036] Embodiment 4:
[0037] Take 100 μL of the D-CQDs stock solution obtained in Example 2, add 0-200 μL of the test solution containing metronidazole (MNZ) (0.01 mol / L), dilute the solution to 10 mL with ultrapure water, shake well and place 4 mL of the solution in a cuvette. After standing for 2 minutes, use a VARIAN fluorescence spectrophotometer to select a test voltage of 550 V, an excitation and emission slit of 5 nm, and an excitation wavelength of 335-365 nm for fluorescence spectrum testing, and obtain the fluorescence emission spectrum data in response to different MNZ concentrations (see Figure 6 (a)); Substitute the peak value of the D-CQDs emission peak into (F0-F) / F0 (F0 represents the initial fluorescence intensity of D-CQDs, and F represents the fluorescence intensity after adding MNZ), and establish a linear relationship with the concentration of the added MNZ solution (F0-F) / F0=b+aX (b is the intercept, a is the slope, and X is the concentration of the MNZ solution to be tested) to calculate the detection limit (LOD) and obtain the linear correlation coefficient (R2 ); and the MNZ content was calculated by the fluorescence intensity results.
[0038] The results showed that the D-CQDs can detect MNZ with high selectivity (see Figure 4 (b)), the corresponding detection linear range is 1.0×10 -5 mol / L~2.0×10 -4 mol / L (see Figure 6 (b) ), with a limit of detection (LOD) of 0.66 nmol / L and a corresponding linear correlation coefficient of 0.98494.
Claims
1. A method for preparing a chiral carbon quantum dot fluorescent probe and selectively detecting metronidazole, characterized in that: The specific steps are: (1) Dissolve 0.1-0.5 g chiral glutamic acid and 0.5-5.0 g sugarcane molasses in 20-80 mL ultrapure water and mix well. (2) placing the solution obtained in step (1) in an ultrasonic machine for ultrasonic treatment, then transferring the ultrasonicated solution to a polytetrafluoroethylene liner, and finally placing it in a stainless steel shell of a reactor and reacting it in a constant temperature forced air drying oven at 120-220°C for 6-18 hours. After the reaction is completed and cooled to room temperature, filtering and centrifuging are performed to obtain a chiral carbon quantum dot (Ch-CQDs) stock solution based on sugarcane molasses; (3) Take 100 μL of the Ch-CQDs solution obtained in step (2), add 0-200 μL of the test solution containing metronidazole (MNZ) (0.01 mol / L), dilute the solution to 10 mL with ultrapure water, shake well and place 4 mL of the solution in a cuvette. After standing for 2 minutes, use a VARIAN fluorescence spectrophotometer to select a test voltage of 550 V, an excitation and emission slit of 5 nm, and an excitation wavelength of 335-365 The fluorescence spectrum test was carried out under the condition of 100 nm to obtain the fluorescence emission spectrum data in response to different MNZ concentrations; the intensity of the Ch-CQDs emission peak (i.e., peak value) was substituted into (F0-F) / F0 (F0 represents the initial fluorescence intensity of Ch-CQDs, and F represents the fluorescence intensity after adding MNZ), and a linear relationship (F0-F) / F0=b+aX (b is the intercept, a is the slope, and X is the concentration of the MNZ solution to be tested) was established with the concentration of the MNZ solution to be tested to calculate the detection limit (LOD) and obtain the linear correlation coefficient (R 2 ); and the MNZ content was calculated by the fluorescence intensity results.
2. The method according to claim 1, characterized in that The chiral glutamate is L-glutamate or D-glutamate.
3. The method according to claim 1, characterized in that The linear range of the metronidazole solution to be tested is 1.0×10 -5 mol / L~2.0×10 -4 mol / L.
4. The method according to claim 1, characterized in that: The metronidazole drug purity is 99%.
5. The method according to claim 1, characterized in that The purity of the chiral glutamate drug is 98%.
6. The chiral carbon quantum dots in claim 1 are spherical in shape and have a uniform particle size distribution. Under optimal conditions, the particle size is between 2.25 nm and 4.55 nm, the average particle size is 3.30 nm, and the interplanar spacing is 0.22 nm.
7. The method according to claim 1, characterized in that The minimum detection limit (LOD) of Ch-CQDs for metronidazole can reach 0.66 μmol / L, and the corresponding linear correlation coefficient (R 2 ) can reach 0.98494.