CN-122016776-A - Construction method and application of organophosphorus pesticide detection sensor assisted by smart phone

Abstract

A construction method and application of an organophosphorus pesticide detection sensor assisted by a smart phone belong to the technical field of analysis and detection. The method comprises the steps of firstly synthesizing UIO-66@MnO 2 nano enzyme, which has higher oxide-like enzyme activity, so as to catalyze and oxidize 3,3', 5' -tetramethyl benzidine (TMB) to develop Color, catalyzing thiocholine hydrolysis by utilizing acetylcholinesterase to generate a reducing substance, inhibiting Color reaction of TMB, enabling an organophosphorus pesticide to specifically inhibit acetylcholinesterase activity so as to recover Color development, shooting a reaction solution through Color Grab software of a smart phone, outputting RGB values, calculating gray values, establishing a linear relation between the gray values and pesticide concentration, and realizing quantitative detection of the organophosphorus pesticide. The sensor constructed by the invention has high sensitivity, good selectivity, simple and convenient operation and low cost, can be successfully applied to the rapid detection of organophosphorus pesticides in food and environmental samples, and has good practical application prospect.

Inventors

• WANG YUANYUAN
• Zhao Biyao
• Jia Fangyi
• WANG YU
• WU XIAOYU

Assignees

• 蚌埠医科大学

Dates

Publication Date

20260512

Application Date

20260228

Claims (3)

1. 1. The construction method of the organophosphorus pesticide detection sensor assisted by the smart phone is characterized by comprising the following steps of: (1) Synthesis of UIO-66@MnO 2 nano enzyme: Mixing zirconium tetrachloride, terephthalic acid and 2-amino terephthalic acid according to a molar ratio of 1:11.1:0.8, dispersing in 6-10 mL of N, N-dimethylformamide, adding 60-100 mu L of hydrochloric acid, vigorously stirring, transferring into a polytetrafluoroethylene lining stainless steel autoclave, calcining at 120 ℃ for 12-48 hours, alternately cleaning a product by using N, N-dimethylformamide and water, drying in an oven to obtain UIO-66 powder, dispersing UIO-66 in 2-morpholinoethanesulfonic acid buffer solution, adding 2-5 mM of potassium permanganate, carrying out ultrasonic reaction for 30-40 min, cleaning the product by using water, and drying in the oven to obtain brown UIO-66@MnO 2 nano enzyme; (2) Construction of a smart phone-assisted nano enzyme colorimetric sensor: Mixing 10-20 mu L of organophosphorus pesticides, 100 mU/mL of acetylcholinesterase and 2 mM of thiocholine, incubating for 30-60 min at 37 ℃, adding 10-20 mu G/mL of UIO-66@MnO 2 aqueous dispersion, 0.1-1 mM of TMB, and HAc-NaAc buffer solution with the concentration of 0.1M and the pH of 4.0 at 35 ℃ for reacting for 5-10 min, finally photographing the reaction product by using Color Grab software of a smart phone, outputting R, G, B values, calculating gray values by using a formula Grayscale=0.299 R+0.587G+0.7B, establishing a linear relation between the gray values y and the organophosphorus pesticide concentration x, fitting a linear equation y=kx+b, and calculating a detection limit LOD of the colorimetric sensor method assisted by the smart phone according to the LOD=3 s/k, wherein s is a standard deviation of 11 times of detection, and k is a slope of a blank equation.
2. 2. The application of the intelligent mobile phone-assisted organophosphorus pesticide detection sensor constructed according to the method in organophosphorus pesticide detection in food and environmental samples.
3. 3. The use according to claim 2, characterized by the steps of: Firstly, pretreating a sample; Weighing 0.5-1.0 g of solid sample, cutting up, immersing into a methanol/acetone mixed solution with the volume ratio of 1:1, mixing the solution for 2-5 min by vortex, centrifuging for 5-10 min, and diluting the supernatant with a 2% ethanol-water solution for 50-200 times for later use; measuring 0.5-1.0 mL of liquid sample, filtering with a microporous filter membrane with the thickness of 0.22-0.45 mu m, and diluting for 50-200 times for later use; Mixing 10-20 mu L of pretreated food, an environmental sample and 100 mU/mL of acetylcholinesterase with 2 mM of thiocholine, incubating for 30-60 min at 37 ℃, then adding 10-20 mu G/mL of UIO-66@MnO 2 aqueous dispersion, 0.1-1 mM of TMB and HAc-NaAc buffer solution with the concentration of 0.1M and the pH of 4.0 to react for 5-10 min at 35 ℃, finally photographing the reaction product by using Color Grab software of a smart phone, outputting R, G, B value, calculating gray value by using a formula Grayscale=0.299 R+0.587G+0.7B and substituting the gray value into a linear fitting equation y=kx+b of the step (2), and calculating the concentration x of the organophosphorus pesticide in the food sample; and for an actual sample in which the organophosphorus pesticide is not detected, verifying the accuracy of the method by using a labeled recovery method.

Description

Construction method and application of organophosphorus pesticide detection sensor assisted by smart phone Technical Field The invention relates to a construction method and application of an organophosphorus pesticide detection sensor assisted by a smart phone. Background In recent years, researchers have developed a variety of instrumental analysis techniques for detecting Organophosphorus Pesticides (OPs), including gas chromatography, high performance liquid chromatography, liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry, chemiluminescence, and the like. Although these conventional techniques have achieved sensitive detection of OPs, there are a number of limitations in the detection process that cannot be overcome, such as the need for complicated and costly equipment, complicated sample preparation, lengthy analysis times, excessive detection costs, etc. Therefore, it is of great importance to explore simple, rapid and visual sensing methods for detecting OPs in food. Among many pesticide residue analysis methods, colorimetric analysis is remarkable in that it is simple to operate, quick in response, portable and miniaturized in instrument, and low in cost. However, colorimetry is inherently insensitive, and it is difficult to detect the target concentration at low illuminance, limiting its practical application. In recent years, nanoenzyme-based colorimetric biosensors have received high attention due to their stability, simplicity, adjustability and low cost. The high catalytic activity of the nano-enzyme can convert the target object into a more obvious color-changing output signal to realize visual detection, and the catalytic activity of the nano-enzyme can be regulated by regulating the size, the shape/form, the composition, the molecular weight or forming a compound or a hybrid, so that the rapid, visual and sensitive analysis of OPs is expected to be carried out by constructing a colorimetric sensor based on the nano-enzyme. Point of care (POCT) has important implications in food safety detection, environmental monitoring, disease identification and diagnosis, etc. POCT devices are typically a combination of sensors and miniaturized devices that enable integration of "sample-in-answer-out". Smartphones have many advanced functions including light sensors, high definition cameras, wi-Fi and bluetooth communications, mass storage, touch screens, etc. Thus, a smart phone is not only a common communication tool, but also a convenient digital processing center, which can act as a sensor to meet the limited area of the device. Therefore, the smart phone is used as an aid, and the POCT analysis of OPs is realized with important scientific significance and practical application value. Up to now, some colorimetric sensors based on smart phone assistance have been reported to detect organophosphorus pesticides, such as: Chinese patent CN202410538185.5 discloses a test paper for detecting organophosphorus pesticide in real time, which is assisted by a smart phone, and is prepared from a polyvinyl chloride substrate card, a glass fiber film and a prepared composite nano material. Based on the fact that the organophosphorus pesticide has an inhibition effect on the biological catalytic activity of acetylcholinesterase (AChE), the AChE is used as a signal amplifier, the organophosphorus pesticide can reduce the yield of the AChE for catalyzing hydrolysis of thiocholine (ATCh) to generate thiocholine (TCh), further reduce the inhibition effect of the TCh on the activity of composite nano-material peroxidase, and realize visual detection of the organophosphorus pesticide through a TMB oxidation method. Article Wang, y; chen, j., liu, y., zhang, r., hong, j., zhao, y., microchip, acta 2025, 192 (11), 714 a new paper-based colorimetric sensor based on core-shell metal-organic frameworks (MOFs) coated with a virtual molecularly imprinted polymer (DMIP) was synthesized for detection of organophosphorus pesticides. MOFs are used as cores, the sensitivity of the sensor is improved due to the inherent advantages of high catalytic activity, stability and the like, and meanwhile, the limitation of MOFs in single-substrate detection is effectively overcome by introducing MIP. The sensor combines color response and quantitative analysis through the smart phone, and 6 OPs are successfully detected in agricultural products. Article Jing, W.; Qiang, S.; Jia, Z.; Shi, Q. H.; Meng, X.; Yu, M.; Ma, H.; Zhao, K.; Dai, Y. Sens. Actuators B, Chem. 2023, 389, 133857. developed a nanoenzyme array sensor based on Ag 2 O nanospheres, using Ag 2 O with oxidase-like activity to catalyze the reaction system of TMB, O-phenylenediamine and 2,2' -biazo-bis-3-ethylbenzothiazoline-6-sulfonic acid, using a smart phone with a camera to record and analyze the colorimetric results of the sensor array for OPs detection. The article Song, d., tian, t., yang, x., wang, l., sun, y., li, y., huang, h. Food chem, 2023, 4