CN-122010830-A - Photo-controlled electrochemical molecular probe, preparation method thereof and application thereof in detection of copper ions

Abstract

The invention belongs to the technical field of molecular analysis and detection of organic probes, and discloses a light-operated electrochemical molecular probe (TPMP), a preparation method thereof and application thereof in detection of copper ions (Cu 2+ ). The molecular structural formula of the probe is as follows: The compound 1 is prepared by the reaction of hydroquinone and 2-nitrobenzyl bromide, and then the compound 1 and pyridine formyl chloride hydrochloride are subjected to esterification reaction under the catalysis of triethylamine, so that a target product is obtained. The probe realizes light-operated opening type electrochemical detection of Cu 2+ based on a sequential response mechanism of Cu 2+ specific recognition-365 nm ultraviolet light activation, has no electrochemical signal in the dark, quantitatively releases electroactive substances after light activation and generates remarkable response, has a detection limit as low as 30 nM, has ultrahigh selectivity on Cu 2+ , and can effectively resist the interference of biological matrixes. The method is applied to quantitative detection of free Cu 2+ in the sea horse dialysis liquid of the mice of the Alzheimer Disease (AD) model.

Inventors

• DONG HUI
• HUANG HUAWEI
• ZHAO LE
• WANG TAO
• WEI XIUHUA
• CHANG ZHU
• ZHANG YINTANG
• ZHOU YANLI
• XU MAOTIAN

Assignees

• 商丘师范学院

Dates

Publication Date

20260512

Application Date

20260305

Claims (6)

1. 1. The light-operated electrochemical molecular probe is characterized by comprising the following molecular structural formula: 。
2. 2. a method of preparing the photo-controlled electrochemical molecular probe of claim 1, by: a. Dissolving hydroquinone and 2-nitrobenzyl bromide in anhydrous acetone under nitrogen atmosphere, adding anhydrous potassium carbonate, stirring at room temperature for reaction, filtering after the reaction is finished, concentrating filtrate under reduced pressure, and purifying a crude product to obtain a compound 1; b. Under the protection of argon, compound 1 is dissolved in anhydrous dichloromethane, cooled in ice salt bath, triethylamine is added, anhydrous dichloromethane solution of pyridine formyl chloride hydrochloride is added dropwise, stirring is carried out, the temperature is raised to room temperature, stirring reaction is continued, quenching reaction is carried out after the reaction is finished, standing is carried out, an organic phase is separated, drying is carried out, decompression concentration is carried out, a crude product is obtained, and the probe TPMP is obtained through purification.
3. 3. The method for preparing the photoelectrochemical molecular probe according to claim 2, wherein in the step a, the molar ratio of hydroquinone, 2-nitrobenzyl bromide and anhydrous potassium carbonate is 1:1.1:2.5, and in the step b, the molar ratio of compound 1, triethylamine and pyridine formyl chloride hydrochloride is 1:1.5:2.0.
4. 4. The use of the photoelectrochemical molecular probe of claim 1 in a Cu 2+ photoelectrochemical detection.
5. 5. The use of the photoelectrochemical molecular probe according to claim 4 in the optically controlled open electrochemical detection of Cu 2+ , wherein the photoelectrochemical molecular probe is used for the quantitative detection of Cu 2+ in the dialysate of the hippocampus of mice in the alzheimer's disease model, or for the quantitative detection of Cu 2+ in body fluids and environmental water samples.
6. 6. The use of the photoelectrochemical molecular probe of claim 5 in a Cu 2+ photoelectrochemical open type electrochemical test, comprising the steps of: a. preparing a modified electrode, namely sequentially carrying out pretreatment of polishing alumina powder, ultrasonic cleaning with ultrapure water and blow-drying with nitrogen on a carbon fiber microelectrode which is abbreviated as CFME, dispersing single-wall carbon nanotubes in ethanol to prepare dispersion liquid by ultrasonic, modifying the dispersion liquid on the surface of the pretreated CFME by adopting a dip coating method, and naturally airing to obtain a CFME/CNT modified electrode; b. Preparing a detection system, namely preparing a TPMP probe working solution and a Cu 2 + standard solution with a serial concentration by taking a pH 7.4 buffer solution as a substrate; c. Sample incubation and photo-activation, namely mixing working solution of the TPMP probe with Cu 2+ standard solution/sample to be tested respectively, incubating at constant temperature, and then irradiating for 300s by adopting 365nm ultraviolet light; d. Electrochemical detection, namely adopting a three-electrode system, adopting CFME/CNT as a working electrode, adopting a saturated KCl Ag/AgCl electrode as a reference electrode, adopting a platinum wire as a counter electrode, carrying out differential pulse voltammetry test by an electrochemical workstation, and recording the characteristic oxidation peak current of hydroquinone at 0.036V; e. And (3) quantitatively analyzing, namely establishing a standard curve according to the linear relation between the oxidation peak current and the concentration of Cu 2+ , and realizing quantitative detection of Cu 2+ in the sample to be detected.

Description

Photo-controlled electrochemical molecular probe, preparation method thereof and application thereof in detection of copper ions Technical Field The invention relates to the technical field of organic probes for analysis and detection, in particular to a light-operated electrochemical molecular probe (TPMP) and a preparation method thereof, which are applied to high-selectivity and high-sensitivity quantitative analysis of free copper ions (Cu 2+) in complex biological samples such as a dialysis solution of a sea horse region of an Alzheimer Disease (AD) model mouse, and provide technical support for research on pathogenesis of neurodegenerative diseases and diagnosis and treatment effect evaluation. Background Alzheimer's Disease (AD) is the most common neurodegenerative disease worldwide, characterized mainly by progressive memory loss, cognitive decline and neuronal damage. Numerous studies have shown that imbalance of copper ion (Cu 2+) homeostasis in the brain is one of the key causative factors of AD, i.e., excessive Cu 2+ can bind to β -amyloid protein, promote its misfolding and aggregation to form neurotoxic oligomers and fibers, while Cu 2+ can catalyze the Fenton reaction to produce reactive oxygen species, triggering oxidative stress, lipid peroxidation and neuronal apoptosis. Therefore, the method realizes the accurate and space-time controllable detection of Cu 2+ in brain, and has important significance for clarifying the pathogenesis of AD and developing effective diagnosis and treatment strategies. In the existing Cu 2+ detection method, the electrochemical method is focused on the advantages of high sensitivity, quick response, low cost, easiness in microminiaturization and the like, but the traditional electrochemical probe has poor selectivity on Cu 2+, is easily interfered by non-target substances in complex biological matrixes, lacks of the capability of time-space regulation and control on the detection process, and limits the application of the electrochemical probe in-vivo analysis. The light-operated molecular probe can realize accurate space-time regulation and control of the detection process by introducing photolytic groups, namely the identification or signal generation capacity of the probe is locked in darkness and unlocked only under the irradiation of specific wavelength light, so that the interference of non-target objects in biological environment can be effectively avoided, and the light-operated molecular probe has unique advantages in biological sample analysis. The reported photo-control probes focus on fluorescence detection, photo-control molecular probes aiming at electrochemical detection are rarely reported, and photo-control electrochemical probes suitable for detecting Cu 2+ in brain of AD model mice are not available. Therefore, there is a need in the art to develop a high-selectivity, high-sensitivity, space-time controllable photo-controlled electrochemical Cu 2+ detection probe to achieve accurate quantification of Cu 2+ in complex biological samples. Disclosure of Invention Aiming at the current state of the art, the invention aims to provide a light-operated electrochemical molecular probe (TPMP) and a preparation method and application thereof, and solves the problems of poor detection selectivity, lack of space-time regulation, large interference of biological matrix and the like of the traditional electrochemical probe on Cu 2+. In order to achieve the aim, the light-operated electrochemical molecular probe integrates a 2-nitrobenzyl photolysis group, a picolinate Cu 2+ recognition group and a Hydroquinone (HQ) electroactive reporter group into a single molecular framework, and realizes light-operated electrochemical detection of Cu 2+ by utilizing a Cu 2+ specific recognition-ultraviolet light activated sequential response mechanism, wherein in darkness, cu 2+ and picolinate groups are subjected to specific coordination catalytic hydrolysis to generate a stable intermediate for retaining the photolysis group, an electroactive site is still locked and has no electrochemical signal, and after 365 nm ultraviolet light irradiation, the 2-nitrobenzyl photolysis group in the intermediate is subjected to irreversible cleavage to quantitatively release free electroactive hydroquinone to generate remarkable open-type electrochemical response, so that high-selectivity and high-sensitivity detection of Cu 2+ is realized. The specific technical scheme is as follows: (1) Design of photo-controlled electrochemical molecular probe (TPMP) The core design of the invention is that a 2-nitrobenzyl photolytic group and a picolinate Cu 2+ recognition group are covalently connected with an HQ electroactive group to construct a single-molecule light-operated electrochemical probe TPMP, and the design basis is as follows: The photolysis unit is characterized in that 2-nitrobenzyl is preferably adopted as a photolysis group, the group has stable structure in darkness, can be