Method for highly-sensitive and rapid detection of pesticide residue based on imprinted metal-organic framework probe

Patent metadata

Field	Value
Publication number	US-2024230542-A1
Application number	US-202118008687-A
Country	US
Kind code	A1
Filing date	Dec 22, 2021
Priority date	Dec 8, 2021
Publication date	Jul 11, 2024
Grant date	—

Abstract

A method for highly-sensitive and rapid detection of a pesticide residue based on an imprinted metal-organic framework (MOF) probe is provided. A molecularly imprinted MOF enzyme-mimic probe is used as a colorimetric probe to catalyze the oxidation of a substrate, thereby enabling a color change of a system; a low-cost filter paper is used as a substrate for supporting the colorimetric probe, including a quality control zone, a standard zone, and a detection zone; in the quality control zone, the optimal colorimetric analysis parameters can be selected according to the temperature, humidity, and light, etc. of an environment to be tested; the standard zone is a standard colorimetric zone obtained through the dropwise addition of standards with different concentrations and is provided to establish a colorimetric analysis mathematical model; and the detection zone is provided for the detection of an actual sample.

First claim

What is claimed is:

1 . A method for highly-sensitive and rapid detection of a pesticide residue based on an imprinted metal-organic framework (MOF) probe, comprising the following steps:
step 1 . 1 : dissolving an MOF and aminopropyltriethoxysilane in ammonia water to obtain a mixed solution; selecting a pesticide standard and denoting the pesticide standard as NY; adding the pesticide standard to the mixed solution, subjecting a resulting mixture to a first stirring, adding tetraethylorthosilicate, and subjecting a resulting mixture to a second stirring; and then centrifuging, washing, and drying to obtain an imprinted MOF enzyme-mimic probe; step 1 . 2 : taking an ordinary filter paper, and dividing the ordinary filter paper into a first zone, a second zone, and a third zone, wherein the first zone is a quality control zone, the second zone is a standard zone, and the third zone is a detection zone; step 1 . 3 : dividing the quality control zone into a first quality control subzone and a second quality control subzone; dividing the first quality control subzone into n zones from left to right that are denoted as H 1 , H 2 , H 3 . . . H n-1 , and H n , respectively; and dividing the second quality control subzone into m zones from left to right that are denoted as I 1 , I 2 , I 3 . . . I m-1 , and I m , respectively, wherein n and m are each an integer greater than 1; step 2 . 1 : establishment of the quality control zone: step 2 . 1 . 1 : determination of an optimal concentration of an imprinted MOF enzyme-mimic probe solution: adding the imprinted MOF enzyme-mimic probe prepared in the step 1 . 1 to ethanol to obtain imprinted MOF enzyme-mimic probe solutions with different concentrations that are denoted as 1, 2 . . . n−1, and n, respectively, adding the imprinted MOF enzyme-mimic probe solutions 1, 2 . . . n−1, and n in a volume V1 dropwise to zones H 1 , H 2 , H 3 . . . H n-1 , and H n of the first quality control subzone, respectively, and allowing the zones to be dried; then dissolving the NY in the step 1 . 1 into water to obtain an NY solution; adding the NY solution in a volume V2 dropwise to each of H 1 , H 2 , H 3 . . . H n-1 , and H n of the first quality control subzone, and allowing a first reaction to occur for a period of time; adding a chromogenic reagent in a volume V3 dropwise to each of H 1 , H 2 , H 3 . . . H n-1 , and H n of the first quality control subzone; observing color changes of the zones H 1 , H 2 , H 3 . . . H n-1 , and H n of the first quality control subzone, acquiring an image and a corresponding RGB value of each of the zones, and further calculating a gray value; and determining a concentration of an imprinted MOF enzyme-mimic probe solution corresponding to a zone with the largest gray value as the optimal concentration of the imprinted MOF enzyme-mimic probe solution, wherein the chromogenic reagent comprises 3,3′,5,5′-tetramethylbenzidine (TMB), hydrogen peroxide (H 2 O 2 ), and NaAc-HAC with a pH of 4.0; step 2 . 1 . 2 : determination of an optimal chromogenic reagent concentration: after the determination of the optimal concentration of the imprinted MOF enzyme-mimic probe solution in the step 2 . 1 . 1 , adding the imprinted MOF enzyme-mimic probe solution with the optimal concentration in a volume V4 dropwise to zones I 1 , I 2 , I 3 . . . I m-1 , and I m of the second quality control subzone, and allowing the zones to be dried; adding the NY solution in the step 2 . 1 . 1 in a volume V5 dropwise to each of I 1 , I 2 , I 3 . . . I m-1 , and I m of the second quality control subzone, and allowing a second reaction to occur for a period of time; adding the chromogenic reagent with different concentrations in a volume V6 dropwise to I 1 , I 2 , I 3 . . . I m-1 , and I m of the second quality control subzone, respectively; observing color changes of I 1 , I 2 , I 3 . . . I m-1 , and I m of the second quality control subzone, acquiring an image and a corresponding RGB value of each of the zones, and further calculating a gray value; and determining a chromogenic reagent concentration corresponding to a zone with the largest gray value as the optimal chromogenic reagent concentration, wherein the chromogenic reagent comprises TMB, H 2 O 2 , and NaAc-HAC with a pH of 4.0; step 2 . 2 : establishment of the standard zone: dividing the standard zone into n zones from top to bottom that are denoted as E 1 , E 2 , E 3 . . . E n-1 , and En, respectively; after the determination of the optimal concentration of the imprinted MOF enzyme-mimic probe solution in the step 2 . 1 . 1 , adding the imprinted MOF enzyme-mimic probe solution with the optimal concentration in a volume V7 dropwise to a surface of each of E 1 , E 2 , E 3 . . . E n-1 , and E n of the standard zone, and allowing the surfaces to be dried; preparing NY solutions with different concentrations, and denoting the NY solutions with different concentrations as C 1 , C 2 . . . C n-1 , and C n ; adding the NY solutions with different concentrations in a volume V8 dropwise to E 1 , E 2 , E 3 . . . E n-1 , and E n of the standard zone, respectively, and allowing a third reaction; and with the optimal chromogenic reagent concentration determined in the step 2 . 1 . 2 , adding the chromogenic reagent in a volume V9 to each of E 1 , E 2 , E 3 . . . E n-1 , and E n of the standard zone, and allowing a fourth reaction, so as to establish a standard colorimetric card for the standard zone, wherein a color of the standard colorimetric card for the standard zone remains unchanged for 20 min or more; step 2 . 3 : acquiring chromogenic images of the NY solutions with different concentrations corresponding to the standard colorimetric card for the standard zone in the step 2 . 2 , and analyzing RGB values of the NY solutions with different concentrations; calculating corresponding Gray values according to equation (1), and denoting the Gray values as G 1 , G 2 , G 3 . . . G n-1 , and G n , respectively,

Gray
=

R
2.2

+

(

1.5
G

)

2.2

+

(

0.6
B

)

2.2

1
+

1.5
2.2

+

0.6
2.2

2.2

,

(
1
)

Assignees

• Univ Jiangsu

Inventors

• Zhang Xinai
• Huang Xueyue
• Shi Jiyong
• Zou Xiaobo
• Huang Xiaowei
• Li Zhihua
• Guo Zhiming
• Zhang Di
• Zhai Xiaodong
• Hu Xuetao
• Shen Tingting

Classifications

• G01N2021/7759

  Dipstick; Test strip · CPC title

• G01N33/52

  Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper {and including single- and multilayer analytical elements (immunological elements G01N33/54386; involving labelled immunochemicals G01N33/58; for haemoglobin or occult blood G01N33/72)} · CPC title

• G01N21/278

  Constitution of standards · CPC title

• B01J31/067

  Molecularly imprinted polymers (catalytic antibodies C12N9/0002) · CPC title

• B01J31/1625

  immobilised by covalent linkages, i.e. pendant complexes with optional linking groups · CPC title