Method for electrochemically determining dopamine on basis of aptamer recognition effect

Abstract

The invention relates to a method and application for electrochemically determining dopamine on the basis of an aptamer recognition effect. The method is characterized by comprising the following steps: adsorbing electrochemical marker thionine onto the surface of gold-platinum (Au@PtNPs) nano particles, fixing sulfydryl DNA1 on the surface of Au@PtNPs to obtain an electrochemical probe (DNA1/Th/Au@PtNPs); adding dopamine aptamer chain DNA2 into an electrochemical probe solution so as to facilitate the supplementary pairing of the DNA1 and the DNA2 to obtain electrochemical probe (DNA2/DNA1/Th/Au@PtNPs) modified by the DNA2, wherein after the dopamine is added into the probe solution modified by the DNA2, the aptamer chain DNA2 is combined with the dopamine, so that the electrochemical probe DNA1/Th/Au@PtNPs is regenerated; immersing a carbon nano-particle-modified gold electrode (CNPs/GE) into the regenerated electrochemical probe DNA1/Th/AuPtNPs solution, wherein due to the adsorption effect of the carbon nano particles and the single-chain DNA1, the electrochemical probe is adsorbed onto the surface of the electrode, the electrochemical signal is detected, and the quantitative determination of dopamine can be realized by the electrochemical method through the intensity of the electrochemical signal. The sensor is high in selectivity and detection sensitivity.

Description

technical field [0001] The invention belongs to the fields of analytical chemistry and electrochemistry, and in particular relates to an electrochemical method for sexually detecting dopamine. Background technique [0002] Dopamine (DA) is an important information transmission substance, the change of its content can lead to some important diseases such as Parkinson's disease and so on. Therefore, the determination of dopamine has always been a research hotspot in the fields of analytical chemistry, biology and medicine. Electrochemical determination of dopamine has high sensitivity, but because a large amount of ascorbic acid (AA) and dopamine coexist in the brain, its oxidation potential on the solid electrode overlaps with dopamine, which seriously interferes with the determination of dopamine content. [0003] In recent years, some methods for detecting dopamine based on aptamer technology have been proposed. Such as photometry (Yu Zheng, Yong Wang, Xiurong Yang, Aptam...

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Problems solved by technology

Such as photometry (Yu Zheng, Yong Wang, Xiurong Yang, Aptamer-based colorimetric biosensing of dopamine using unmodified gold nanoparticles. Sensors and Actuators B, 156(2011) 95-99), fluorescence method (Qin Mu, Hu Xu, Yan Li , Shijian Ma, Xinhua Zhong, Adenosine capped QDs based fluorescent sensor for detection of dopamine with high selectivity and sensitivity. Analyst, 139(2014) 93-98), ELISA (Hoyoung Park, Insook Rhee Paeng, Development of direct competitive enzyme-linked aptamer assay for determination of dopamine in serum. Analytica Chimica Acta, 685 (2011) 65-73; Eunhye Kim, Insook Rhee Paeng, Advantageous sensitivity in the DNA homolog of the RNA dopamine aptamer. Journal of Immunoassay and Immunochemistry, (2014) 83-100), etc. However, most of these detection methods have low sensitivity, tedious operation, and more time-consuming

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