阅读说明：本技术 纳米硒化锌修饰金电极光致电化学传感器制备方法及应用 (Preparation method and application of nano zinc selenide modified gold electrode photo-induced electrochemical sensor ) 是由 混旭 贾毅 孟玉蝉 赵继宽 钟华 张慧 张跃 于 2020-05-07 设计创作，主要内容包括：本发明属于分析化学与光致电化学传感器领域,具体涉及纳米硒化锌修饰金电极光致电化学传感器制备方法及应用。通过超声剥离方法成功剥离出纳米ZnSe,将其修饰到金电极GE上,构建了ZnSe/GE光电化学传感器。该传感器对多巴胺具有选择性响应。方法简单,成本低。(The invention belongs to the field of analytical chemistry and photo-electrochemical sensors, and particularly relates to a preparation method and application of a nano zinc selenide modified gold electrode photo-electrochemical sensor. The nano ZnSe is successfully stripped by an ultrasonic stripping method and is modified on a gold electrode GE, so that the ZnSe/GE photoelectrochemical sensor is constructed. The sensor has a selective response to dopamine. The method is simple and low in cost.)

1. The preparation method of the nano zinc selenide modified gold electrode photo-electrochemical sensor comprises the following steps:

(1) preparation of nano zinc selenide

Weighing 1-200 mg of zinc selenide, dispersing the zinc selenide into a beaker filled with 0.1-200 m of L-L N, N-Dimethylformamide (DMF), stirring for 1-100 min, then carrying out ultrasonic treatment in an ultrasonic instrument for 0.1-48 h, carrying out stripping treatment on the zinc selenide, and finally forming a zinc selenide suspension with the concentration of 0.1-50 mg/m of L-50 mg/m of L;

(2) preparation of nano zinc selenide modified gold electrode

Dropwise adding the zinc selenide dispersion liquid obtained by stripping in a range of 1 mu L-50 mu L on the surface of the polished gold electrode, and naturally drying at room temperature to obtain a gold electrode modified by nano zinc selenide and a photo-electrochemical sensor of the nano zinc selenide modified gold electrode;

(3) when the photoinduced electrochemical sensor is inserted into a PBS solution, photoinduced electrochemical test is carried out to obtain a photoinduced electrochemical signal I₀(ii) a When the photo-induced electrochemical sensor is inserted into a dopamine solution with a certain concentration, a photo-induced electrochemical signal I is obtained, namely I-I₀To analyze the signal, a dopamine assay is performed;

the photoelectrochemical sensor prepared by the method can detect dopamine, so that the invention provides application of the photoelectrochemical sensor in detecting dopamine content.

2. The method for preparing the nano zinc selenide modified gold electrode photo-electrochemical sensor according to claim 1, wherein the nano zinc selenide modified gold electrode photo-electrochemical sensor has the following characteristics:

in the response of 23 small molecules of dopamine, methionine, lysine, threonine, serine, arginine, leucine, valine, isoleucine, proline, phenylalanine, glutamic acid, alanine, cysteine, cystine, tryptophan, asparagine, isoleucine, ascorbic acid, glycine, rutin, threonine and glutathione to the sensor, only the dopamine has obvious enhancement effect on the photoelectrochemical signals.

Technical Field

The invention belongs to the field of analytical chemistry and photo-electrochemical sensors, and particularly relates to a preparation method of a zinc selenide modified gold electrode photo-electrochemical sensor for detecting dopamine. In addition, the invention also relates to a method for measuring dopamine by using the photoinduced electrochemical sensor.

Background

Dopamine is a neurotransmission substance used to help cells deliver pulsatile chemicals. Dopamine is a key neurotransmitter in the hypothalamus and pituitary gland, and the concentration of dopamine in the central nervous system is influenced by psychiatric factors. Research has shown that dopamine is important and widespread in participating in and affecting the physiological functions of the body. It regulates the motor function of human beings, and without its effect, human beings will be difficult to carry out. Human emotion and cognitive abilities including milk secretion, cardiovascular function, gastrointestinal function, regulation of intraocular pressure and retinal transmission of visual information require dopamine to exert regulatory effects. In addition, many effective drugs for treating diseases have been generated around the research of dopamine. Such as dopamine and dopetamine for the treatment of shock caused by blood loss or infection; levodopa treatment of intractable parkinson's disease; neuroleptic agents for the treatment of schizophrenia; the molsidines treat the weakening of gastrointestinal motility and emptying function; dopamine antagonist drugs are used for treating glaucoma, pituitary tumor, and the like. The establishment of a dopamine high-sensitivity detection method has profound significance on the research and development of nervous systems and medicines. There are many analytical methods currently used for dopamine detection: colorimetric method, fluorescence sensing method, electrochemical method, etc. The photo-electrochemical method has the advantages of low price, high response speed, simple operation, high sensitivity and the like, and is expected to be better applied to the detection of dopamine. Therefore, the invention uses the photosensitive material to modify the electrode to prepare the photoelectrochemical sensor for sensitive detection of dopamine, and establishes a new method for measuring dopamine.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a preparation method of a zinc selenide modified electrode photo-electrochemical sensor for detecting dopamine, and a method for detecting dopamine by using the photo-electrochemical sensor.

The purpose of the invention is realized as follows: modifying a gold electrode by using zinc selenide, and constructing a photoinduced electrochemical sensor to realize the determination of dopamine; a preparation method and application of a zinc selenide modified gold electrode photo-electrochemical sensor for detecting dopamine comprise the following steps:

(1) preparation of nano zinc selenide

Weighing 1-200 mg of zinc selenide, dispersing the zinc selenide into a beaker filled with 0.1-200 m of L-L N, N-Dimethylformamide (DMF), stirring for 1-100 min, then carrying out ultrasonic treatment in an ultrasonic instrument for 0.1-48 h, carrying out stripping treatment on the zinc selenide, and finally forming a zinc selenide suspension with the concentration of 0.1-50 mg/m of L-50 mg/m of L, centrifuging the zinc selenide suspension at the rotating speed of 100-24000 r/min for 0.1-120 min, taking out a centrifugal tube, removing a supernatant, adding DMF into the precipitate for washing, repeating the washing for three times, dispersing the obtained nano zinc selenide into the DMF, transferring the obtained nano zinc selenide into a weighing bottle, and placing the nano zinc selenide into the weighing bottle for standby at room temperature.

(2) Preparation of nano zinc selenide modified gold electrode

And (3) dropwise adding the zinc selenide dispersion liquid obtained by stripping in a range of 1 mu L-50 mu L on the surface of the polished gold electrode, and naturally drying at room temperature to obtain the gold electrode modified by the nano zinc selenide.

When the photoinduced electrochemical sensor is inserted into a dopamine solution with a certain concentration, a photoinduced electrochemical signal I is obtained, and the dopamine is measured by taking the I as an analysis signal. The stripped and unstripped ZnSe were characterized as shown in FIG. 1. As can be seen from FIG. 1(A), the stripped ZnSe is a thin random plate structure and is relatively thin. As can be seen from FIG. 1(B), the thickness of the non-peeled ZnSe is significantly thicker than that of the peeled ZnSe, the non-peeled ZnSe is a sheet structure formed by overlapping multiple ZnSe layers, and the black shading in the middle part of the TEM image indicates that the powder ZnSe is not dispersed, and the uneven color indicates that the thickness is greatly different. As can be seen from the comparison of the two, the ultrasonic peeling of ZnSe has a remarkable effect.

The photo-electrochemical activity performance of ZnSe stripped by different strippers is studied in experiments, gold electrodes are modified by stripped ZnSe and non-stripped ZnSe respectively, 15 mu L ZnSe suspension is dripped on the surfaces of the electrodes, the electrodes are dried at room temperature, and photo-electrochemical signals of the stripped and non-stripped ZnSe modified electrodes are measured in PBS with the pH value of 7.4 and containing dopamine respectively.

As shown in FIG. 2, in PBS, the photoelectrochemical signal of the bare electrode (A) is very small, but the signal values of the stripped ZnSe modified electrode (C) and the non-stripped ZnSe modified electrode (B) are increased, and the signal value of the stripped ZnSe modified electrode is larger than that of the non-stripped ZnSe modified electrode, which indicates that ZnSe has a certain photoelectrochemical property and the photoinduced property of the stripped ZnSe is stronger. After DA is added into PBS, the photocurrent signals of the bare electrodes have no obvious change (D), and the photocurrent signals of the ZnSe modified electrodes ((E) and (F)) are obviously increased, wherein the photocurrent signals of the stripped ZnSe modified electrode (E) and the non-stripped ZnSe modified electrode (F) reach 1588nA and 756nA, and compared with the photocurrent value without DA, the photocurrent value is increased by about 50 times. Therefore, the photo-electrochemical performance of the stripped ZnSe is better than that of the non-stripped ZnSe; DA has obvious enhancement effect on ZnSe photo-induced electrochemical signals.

The photoelectrochemical sensor prepared by the method can detect dopamine, so that the invention provides application of the photoelectrochemical sensor in detecting dopamine content.

Compared with the prior art, the photo-induced electrochemical sensor has the following advantages and remarkable progress: zinc selenide as a nano material with excellent photoelectric properties has lower biological toxicity compared with other II-VI group nanocrystals, especially compared with CdSe, so that the zinc selenide has greater application value in biomedicine and other biological aspects. In addition, zinc selenide has a very stable photo-induced electrochemical signal, so that the photo-induced electrochemical sensor designed by the invention has high stability. In addition, as can be seen from the experimental photo-electrochemical signal intensity (fig. 7), when the sensor of the present invention is used for detecting other amino acids or small molecules, the photocurrent signal is much lower than that of detecting dopamine, which indicates that the sensor has high selectivity for detecting dopamine. Therefore, the preparation method and the application of the zinc selenide modified gold electrode photo-electrochemical sensor for detecting dopamine have good development prospects.

The PBS concentration used above was 10mM, over Na₂HPO₄、Na₂HPO₄And NaCl, wherein the concentration of NaCl is 0.9%.

Drawings

FIG. 1 is a transmission electron micrograph of zinc selenide. Zinc selenide (a) after exfoliation, zinc selenide (B) without exfoliation.

FIG. 2 is a photo-induced electrochemical signal response curve of a ZnSe modified gold electrode. A. B, C are photo-induced electrochemical signals of bare gold electrode, un-stripped ZnSe modified gold electrode and stripped ZnSe modified gold electrode in PBS solution; D. e, F are the photo-induced electrochemical signal response curves of the bare gold electrode, the stripped ZnSe modified gold electrode and the un-stripped ZnSe modified gold electrode in the PBS solution containing DA respectively.

Fig. 3 potential optimization. Left panel, from A to G, at-0.3V-0.3V potential modifies the signal of the electrode in DA in PBS; signals from a to g at potentials of-0.3V-0.3V for the bare electrode in PBS solution in DA. The right graph is a signal difference broken line graph of the modified electrode and the bare electrode when the potential is-0.3V-0.3V.

Figure 4pH optimization. Left panel, from a to E, signal of modified electrode in PBS solution of DA at pH 6.5,7.0,7.4,8.0, 8.5; signal of bare electrode in PBS solution of DA at pH 6.5,7.0,7.4,8.0,8.5 from a to e. The right graph is a signal difference line graph of the modified electrode and the bare electrode at pH 6.5,7.0,7.4,8.0, 8.5.

In the left graph, A-E are photoinduced electrochemical response curves of the stripped ZnSe modified electrode in the DA PBS solution when the volume of the modifier is 5, 10, 15, 20 and 25 mu L, a-E are photoinduced electrochemical response curves of a bare electrode in the DA PBS solution, and the right graph is a signal difference value broken line graph of the modified electrode and the bare electrode when the volume of the modifier is 5, 10, 15, 20 and 25 mu L.

FIG. 6 is a graph of photoelectrochemical signal as a function of dopamine concentration the left panel has the abscissa of concentration c in mol/L.

FIG. 7 selectivity of photo-electrochemical sensor A to x are Dopamine (DA), blank solution, methionine (Met), lysine (L ys), threonine (Thr), serine (Ser), arginine (Arg), leucine (L ou), valine (Val), isoleucine (Ile), proline (Pro), phenylalanine (Phe), glutamic acid (Glu), alanine (Ala), cysteine (Cys), cystine (Cys-Cys), tryptophan (Trp), asparagine (Asn), isoleucine (Iso), Ascorbic Acid (AA), glycine (Gly), Rutin (Rutin), threonine (Thr), glutathione (L-Glu), respectively, and the concentration of amino acid or small molecule is 1 mM.

Detailed Description

The invention is further illustrated, but is not to be construed as being further limited, by the following specific examples.