Preparation method and application of organic phase electrodeposition silver microelectrode for detecting carotenal

Abstract

The invention discloses a method for preparing an organic phase electrodeposited silver microelectrode for detecting carotene, which comprises the following steps: preparing an electrolyte and preparing a SERS active microelectrode by electrodeposition. The method proposed by the invention can prepare a silver nanostructure on CFME in a convenient way. The micro-size multi-technique coupled detection method has low cost, simple operation and high detection efficiency, and can be widely used in the fields of food safety and biomedicine.

Description

Technical Field

[0001] The invention belongs to the technical field of food safety analysis and chemical detection sensing, and specifically relates to a preparation method of an organic phase electrodeposited silver microelectrode for detecting carotene and application thereof. Background Art

[0002] Carotenoids (β-carotene) not only have antioxidant and free radical scavenging properties, but can also be symmetrically cleaved into vitamin A. However, if β-carotene undergoes asymmetric cleavage, two β-apocarotenal molecules with different chain lengths are formed, such as trans-β-Apo-8′-carotenal. Studies have shown that carotenal has serious side effects on cells. Under strong oxidative stress conditions, the attack of free radicals on β-carotene leads to the formation of many asymmetric decomposition products, which are carcinogenic and also show cytotoxic and genotoxic effects on primary rat hepatocytes. In addition, carotenal has a statistically significant effect at the micronucleus level at 0.1, 1 and 5 μM, and also induces chromosome aberrations at 0.1, 1 and 10 μM. Therefore, it is very urgent to quickly and accurately detect carotenal qualitatively and quantitatively in the cell microenvironment, and there is still no report on the microsensor for detecting carotenal.

[0003] The present invention uses carbon fiber (CFME) as an electrode carrier, designs a small, uniform and dense silver nanostructure that is electrodeposited on CFME in an organic solution, and combines the electrical enrichment technology with the SERS active microelectrode to develop a new method for detecting carotene by organic phase electrodeposited silver microelectrode SERS. The method has the characteristics of qualitative and quantitative analysis of carotene with toxic side effects, and can monitor low-concentration metabolites of carotene in the cell environment. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing an organic phase electrodeposition microelectrode for detecting carotenal.

[0007] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing an organic phase electrodeposited silver microelectrode for detecting carotenal, which comprises the following steps:

[0008] preparing an electrolyte: dissolving silver nitrate in anhydrous ethanol to obtain an electrodeposition electrolyte containing silver ions;

[0009] Preparation of SERS active microelectrodes by electrodeposition: The carbon fiber microelectrodes are strictly cleaned, dried, and then electrochemically activated, followed by electrodeposition. The electrodeposition electrolyte prepared in the prepared electrolyte is used in the electrodeposition. After the electrodeposition is completed, the microelectrodes are rinsed and dried to obtain SERS active microelectrodes.

[0010] As a preferred solution of the method for preparing the organic phase electrodeposited silver microelectrode for detecting carotenal described in the present invention, wherein: in the preparation of the electrolyte, the concentration of silver ions in the electrodeposition electrolyte is 0.5-10 mM.

[0011] As a preferred embodiment of the method for preparing the organic phase electrodeposited silver microelectrode for detecting carotenal described in the present invention, wherein: in the preparation of the electrolyte, the concentration of silver ions in the electrodeposition electrolyte is 1 mM.

[0012] As a preferred embodiment of the method for preparing the organic phase electrodeposited silver microelectrode for detecting carotenal of the present invention, in which: in preparing the SERS active microelectrode by electrodeposition, the deposition potential selected by the electrodeposition is -0.6 to -0.1V.

[0013] As a preferred embodiment of the method for preparing the organic phase electrodeposited silver microelectrode for detecting carotenal of the present invention, in which: in preparing the SERS active microelectrode by electrodeposition, the deposition potential selected by the electrodeposition is -0.28 to -0.1V.

[0014] As a preferred solution of the method for preparing the organic phase electrodeposited silver microelectrode for detecting carotenal described in the present invention, wherein: in preparing the SERS active microelectrode by electrodeposition, the deposition potential selected by the electrodeposition is -0.164V.

[0015] The present invention also provides the following technical solution: an application of an organic phase electrodeposition silver microelectrode for detecting carotenal.

[0016] The present invention provides the following technical solution: an application of an organic phase electrodeposited silver microelectrode for detecting carotene, which comprises the following steps:

[0017] Prepare carotene stock solution: dilute the carotene stock solution with electrolyte solution, mix well and transfer to the detection cell.

[0018] Construction of detection system: Platinum wire was used as the counter electrode, Ag / Ag Cl was used as the reference electrode, and CFME-dAg prepared by electrodeposition was used as the working electrode to construct the detection system;

[0019] Quantitative detection of carotene: Place the constructed detection system under a confocal microscope, select a 10× lens, a 532nm laser, and adjust different laser powers to record the Raman signal of carotene on the microelectrode surface. Compare the Raman signal strength, signal peak position and ratio between signal peaks of carotene at different potentials, and then qualitatively and quantitatively analyze the carotene;

[0020] Calculation of carotenal concentration: Carotenal molecules were electrically enriched on the CFME-dAg surface at the optimal potential, the microelectrode was placed under the 10× lens of the confocal microscope, the optimal power laser (532nm) was selected, and the Raman signal was collected 5 times at each point and the average value was taken. The concentration of carotenal was quantified by the intensity change of the Raman signal.

[0021] As a preferred method for the application of the organic phase electrodeposited silver microelectrode for detecting carotene aldehyde described in the present invention, wherein: in the quantitative detection of carotene aldehyde, in the constructed detection system, it is set to 0V and maintained for 5 to 20 minutes to electrically drive the adsorption and enrichment of carotene aldehyde molecules in the solution.

[0022] As a preferred method for the application of the organic phase electrodeposited silver microelectrode for detecting carotene as described in the present invention, wherein: in the quantitative detection of carotene, in the constructed detection system, it is to set 0V and maintain it for 10 minutes to electrically drive the adsorption and enrichment of carotene molecules in the solution.

[0023] Beneficial effects of the invention: The invention proposes a method for detecting carotene aldehyde by SERS using an organic phase electrodeposited silver microelectrode, prepares a silver nanostructure on CFME in a convenient way, and achieves highly selective and ultrasensitive detection of carotene aldehyde with toxic side effects by regulating the potential. The micro-sized multi-technique coupled detection method has low cost, simple operation, and high detection efficiency, and can be widely used in the fields of food safety and biomedicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0025] Figure 1 A schematic diagram of the preparation of an organic phase electrodeposited silver microelectrode and the SERS detection of carotene provided in an embodiment of the present invention;

[0026] Figure 2 The scanning electron microscope images, element EDS and mapping images of CFME-dAg prepared at different deposition times in the embodiments of the present invention are shown;

[0027] In the figure, a and b are scanning electron microscope images of CFME-dAg prepared at 120 s, c is a scanning electron microscope image of CFME-dAg prepared at 60 s, d is a scanning electron microscope image of CFME-dAg prepared at 240 s, e is a scanning electron microscope image of CFME-dAg prepared at 360 s, and f is an element EDS and mapping image of CFME-dAg at a deposition time of 120 s;

[0028] Figure 3 (a) are scanning electron micrographs of blank CFME in the example, (b) are scanning electron micrographs of CFME-dAd electrodeposited with 1 mM silver ions in aqueous solution, (c) and (d) are scanning electron micrographs of CFME-dAg electrodeposited with 10 mM silver ions in ethanol solution in Example 3;

[0029] In the figure, a is a blank CFME in Example 1, b is a scanning electron microscope image of CFME-dAd electrodeposited with 1 mM silver ions, c is a scanning electron microscope image of CFME-dAg prepared at 60 s, and d is a scanning electron microscope image of CFME-dAg prepared at 240 s;

[0030] Figure 4 The scattering spectra of silver nanoparticles under a dark field microscope of CFME-dAg prepared at different deposition times in Example 1 (a), the scattering spectra of silver nanoparticles under a dark field microscope of CFME-dAg electrodeposited at different silver ion concentrations (b), the SERS images of two carotenoids on the surface of CFME-dAg under applied potential conditions (c), and the SERS images of carotene on CFME-dAg at different deposition times (d);

[0031] In the figure, a is the scattering spectra of silver nanoparticles of CFME-dAg prepared at different deposition times under a dark field microscope, b is the scattering spectra of silver nanoparticles of CFME-dAg electrodeposited at different silver ion concentrations under a dark field microscope, c is the SERS images of two carotenoids on the surface of CFME-dAg under applied potential conditions, and d is the SERS image of carotene on CFME-dAg at different deposition times;

[0032] Figure 5 The SERS images of carotene aldehyde with different concentrations in Example 1 with and without potential applied on CFME-dAg;

[0033] Figure 6The scanning electron microscopy image (a) of CFME-dAg electrodeposited with 0.5 mM silver ions in ethanol solution of Example 2 and the SERS signal of carotene detected by the electrode (b);

[0034] In the figure, a is a scanning electron microscope image of CFME-dAg electrodeposited with 0.5 mM silver ions in an ethanol solution of Example 2, and b is a SERS signal image of the electrode detecting carotene;

[0035] Figure 7 The SERS signal of CFME-dAg electrodeposited with 10 mM silver ions in ethanol solution in Example 3 for detecting carotene and the comparison with electrodes prepared with other electrolytes;

[0036] Figure 8 The Raman signals of CFME-dAg to carotene aldehyde were obtained at different deposition potentials in 1 mM silver ion ethanol solution electrolyte for the example. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0040] Example 1

[0041] (1) preparing an electrolyte: weighing silver nitrate (Ag NO3) and dissolving it in anhydrous ethanol to prepare an electrodeposition organic phase electrolyte with a silver ion concentration of 1 mM for preparing a highly SERS active silver nanostructure on the carbon fiber surface;

[0042] (2) Preparation of SERS-active microelectrodes by electrodeposition: Before the electrodeposition experiment, the carbon fiber microelectrode (CFME) needs to be strictly cleaned. The CFME was immersed in 400μL acetone, 400μL 3M nitric acid (HNO3), 400μL 1M KOH and 1.5mL ultrapure water, and ultrasonically treated for 1 min respectively, with the frequency of ultrasonic treatment being 60Hz. After cleaning, the CFME was dried at room temperature and then electrochemically activated, that is, in 0.5M H2SO4, the constant potential method was used to maintain 2V and -1V for 30s and 10s respectively. Subsequently, the CFME was cyclically scanned 14 times in the potential range of 0 to 1V by cyclic voltammetry. When the performance of the product was abnormal or under other appropriate conditions, more cycles were performed. After the electrode activation was completed, the electrodeposition operation was performed immediately. With CFME as the working electrode, platinum wire as the counter electrode, and Hg / HgSO4 as the reference electrode, the deposition potential was -0.164 V and the deposition time was 120 s in the anhydrous ethanol solution supporting electrolyte configured in the above (1) by constant potential method. The deposited CFME-dAg was rinsed with pure water several times, dried at room temperature, and stored in a dark place;

[0043] (3) Electrical enrichment of carotene aldehyde molecules: Select pH 7.0 PBS as the supporting electrolyte, and use this electrolyte to dilute the carotene aldehyde stock solution (ethanol solution). After mixing, transfer it to the detection cell, use platinum wire as the counter electrode, Ag / AgCl as the reference electrode, and the CFME-dAg prepared in step (2) as the working electrode to construct a detection system. The carotene aldehyde molecules in the solution are electrically driven to adsorb and enrich by setting 0V and maintaining the potential for 10 minutes;

[0044] (4) Quantitative detection of carotene: Place the CFME-dAg after step (3) under a confocal microscope, select a 10× lens, a 532nm laser, and adjust the laser power to 1.0mW to record the Raman signal of carotene on the microelectrode surface. Compare the Raman signal strength, signal peak position and ratio of each signal peak of carotene at a potential of 0 to -1.0V, and then qualitatively analyze the carotene;

[0045] (5) The CFME-dAg that has been enriched in step (3) at a potential of 0 V is placed under a 10× confocal microscope with a power of 1.0 mW and a laser of 532 nm. Raman signals are collected 5 times at each point and the average value is taken. The concentration of carotenal is quantified by the intensity change of the Raman signal.

[0046] Example 2

[0047] (1) preparing an electrolyte: weighing silver nitrate (Ag NO3) and dissolving it in anhydrous ethanol to prepare an electrodeposition organic phase electrolyte with a silver ion concentration of 0.5 mM for preparing a highly SERS-active silver nanostructure on the carbon fiber surface;

[0048] (2) Preparation of SERS-active microelectrodes by electrodeposition: Before the electrodeposition experiment, the carbon fiber microelectrode (CFME) needs to be strictly cleaned. The CFME was immersed in 400μL acetone, 400μL 3M nitric acid (HNO3), 400μL 1M KOH and 1.5mL ultrapure water, and ultrasonically treated for 1 min respectively, with the frequency of ultrasonic treatment being 60Hz. After cleaning, the CFME was dried at room temperature and then electrochemically activated, that is, in 0.5M H2SO4, the constant potential method was used to maintain 2V and -1V for 30s and 10s respectively. Subsequently, the CFME was cyclically scanned 14 times in the potential range of 0 to 1V by cyclic voltammetry. When the performance of the product was abnormal or under other appropriate conditions, more cycles were performed. After the electrode activation was completed, the electrodeposition operation was performed immediately. With CFME as the working electrode, platinum wire as the counter electrode, and Hg / HgSO4 as the reference electrode, the deposition potential was -0.164 V and the deposition time was 120 s in the anhydrous ethanol solution supporting electrolyte configured in the above (1) by constant potential method. The deposited CFME-dAg was rinsed with pure water several times, dried at room temperature, and stored in a dark place;

[0049] (3) Electrical enrichment of carotene aldehyde molecules: Select pH 7.0 PBS as the supporting electrolyte, and use this electrolyte to dilute the carotene aldehyde stock solution (ethanol solution). After mixing, transfer it to the detection cell, use platinum wire as the counter electrode, Ag / AgCl as the reference electrode, and the CFME-dAg prepared in step (2) as the working electrode to construct a detection system. The carotene aldehyde molecules in the solution are electrically driven to adsorb and enrich by setting 0V and maintaining the potential for 10 minutes;

[0050] (4) Quantitative detection of carotene: Place the CFME-dAg after step (3) under a confocal microscope, select a 10× lens, a 532nm laser, and adjust the laser power to 1.0mW to record the Raman signal of carotene on the microelectrode surface. Compare the Raman signal strength, signal peak position and ratio of each signal peak of carotene at a potential of 0 to -1.0V, and then qualitatively analyze the carotene;

[0051] (5) The CFME-dAg that has been enriched in step (3) at a potential of 0 V is placed under a 10× confocal microscope with a power of 1.0 mW and a laser of 532 nm. Raman signals are collected 5 times at each point and the average value is taken. The concentration of carotenal is quantified by the intensity change of the Raman signal.

[0052] Example 3

[0053] (1) preparing an electrolyte: weighing silver nitrate (Ag NO3) and dissolving it in anhydrous ethanol to prepare an electrodeposition organic phase electrolyte with a silver ion concentration of 10 mM for preparing a highly SERS-active silver nanostructure on the carbon fiber surface;

[0054] (2) Preparation of SERS-active microelectrodes by electrodeposition: Before the electrodeposition experiment, the carbon fiber microelectrode (CFME) needs to be strictly cleaned. The CFME was immersed in 400μL acetone, 400μL 3M nitric acid (HNO3), 400μL 1M KOH and 1.5mL ultrapure water, and ultrasonically treated for 1 min respectively, with the frequency of ultrasonic treatment being 60Hz. After cleaning, the CFME was dried at room temperature and then electrochemically activated, that is, in 0.5M H2SO4, the constant potential method was used to maintain 2V and -1V for 30s and 10s respectively. Subsequently, the CFME was cyclically scanned 14 times in the potential range of 0 to 1V by cyclic voltammetry. When the performance of the product was abnormal or under other appropriate conditions, more cycles were performed. After the electrode activation was completed, the electrodeposition operation was performed immediately. With CFME as the working electrode, platinum wire as the counter electrode, and Hg / HgSO4 as the reference electrode, the deposition potential was -0.164 V and the deposition time was 120 s in the anhydrous ethanol solution supporting electrolyte configured in the above (1) by constant potential method. The deposited CFME-dAg was rinsed with pure water several times, dried at room temperature, and stored in a dark place;

[0055] (3) Electrical enrichment of carotene aldehyde molecules: Select pH 7.0 PBS as the supporting electrolyte, and use this electrolyte to dilute the carotene aldehyde stock solution (ethanol solution). After mixing, transfer it to the detection cell, use platinum wire as the counter electrode, Ag / AgCl as the reference electrode, and the CFME-dAg prepared in step (2) as the working electrode to construct a detection system. The carotene aldehyde molecules in the solution are electrically driven to adsorb and enrich by setting 0V and maintaining the potential for 10 minutes;

[0056] (4) Quantitative detection of carotene: Place the CFME-dAg after step (3) under a confocal microscope, select a 10× lens, a 532nm laser, and adjust the laser power to 1.0mW to record the Raman signal of carotene on the microelectrode surface. Compare the Raman signal strength, signal peak position and ratio of each signal peak of carotene at a potential of 0 to -1.0V, and then qualitatively analyze the carotene;

[0057] (5) The CFME-dAg that has been enriched in step (3) at a potential of 0 V is placed under a 10× confocal microscope with a power of 1.0 mW and a laser of 532 nm. Raman signals are collected 5 times at each point and the average value is taken. The concentration of carotenal is quantified by the intensity change of the Raman signal.

[0058] Example 4

[0059] (1) preparing an electrolyte: weighing silver nitrate (Ag NO3) and dissolving it in anhydrous ethanol to prepare an electrodeposition organic phase electrolyte with a silver ion concentration of 1 mM for preparing a highly SERS active silver nanostructure on the carbon fiber surface;

[0060] (2) Preparation of SERS-active microelectrodes by electrodeposition: Before the electrodeposition experiment, the carbon fiber microelectrode (CFME) needs to be strictly cleaned. The CFME was immersed in 400μL acetone, 400μL 3M nitric acid (HNO3), 400μL 1M KOH and 1.5mL ultrapure water, and ultrasonically treated for 1 min respectively, with the frequency of ultrasonic treatment being 60Hz. After cleaning, the CFME was dried at room temperature and then electrochemically activated, that is, in 0.5M H2SO4, the constant potential method was used to maintain 2V and -1V for 30s and 10s respectively. Subsequently, the CFME was cyclically scanned 14 times in the potential range of 0 to 1V by cyclic voltammetry. When the performance of the product was abnormal or under other appropriate conditions, more cycles were performed. After the electrode activation was completed, the electrodeposition operation was performed immediately. With CFME as the working electrode, platinum wire as the counter electrode, and Hg / HgSO4 as the reference electrode, the deposition potential was -0.1 V and the deposition time was 120 s in the anhydrous ethanol solution supporting electrolyte configured in the above (1) by constant potential method. The deposited CFME-dAg was rinsed with pure water several times, dried at room temperature, and stored in a dark place;

[0061] (3) Electrical enrichment of carotene aldehyde molecules: Select pH 7.0 PBS as the supporting electrolyte, and use this electrolyte to dilute the carotene aldehyde stock solution (ethanol solution). After mixing, transfer it to the detection cell, use platinum wire as the counter electrode, Ag / AgCl as the reference electrode, and the CFME-dAg prepared in step (2) as the working electrode to construct a detection system. The carotene aldehyde molecules in the solution are electrically driven to adsorb and enrich by setting 0V and maintaining the potential for 10 minutes;

[0062] (4) Quantitative detection of carotene: Place the CFME-dAg after step (3) under a confocal microscope, select a 10× lens, a 532nm laser, and adjust the laser power to 1.0mW to record the Raman signal of carotene on the microelectrode surface. Compare the Raman signal strength, signal peak position and ratio of each signal peak of carotene at a potential of 0 to -1.0V, and then qualitatively analyze the carotene;

[0063] (5) The CFME-dAg that has been enriched in step (3) at a potential of 0 V is placed under a 10× confocal microscope with a power of 1.0 mW and a laser of 532 nm. Raman signals are collected 5 times at each point and the average value is taken. The concentration of carotenal is quantified by the intensity change of the Raman signal.

[0064] Example 5

[0065] (1) preparing an electrolyte: weighing silver nitrate (Ag NO3) and dissolving it in anhydrous ethanol to prepare an electrodeposition organic phase electrolyte with a silver ion concentration of 1 mM for preparing a highly SERS active silver nanostructure on the carbon fiber surface;

[0066] (2) Preparation of SERS-active microelectrodes by electrodeposition: Before the electrodeposition experiment, the carbon fiber microelectrode (CFME) needs to be strictly cleaned. The CFME was immersed in 400μL acetone, 400μL 3M nitric acid (HNO3), 400μL 1M KOH and 1.5mL ultrapure water, and ultrasonically treated for 1 min respectively, with the frequency of ultrasonic treatment being 60Hz. After cleaning, the CFME was dried at room temperature and then electrochemically activated, that is, in 0.5M H2SO4, the constant potential method was used to maintain 2V and -1V for 30s and 10s respectively. Subsequently, the CFME was cyclically scanned 14 times in the potential range of 0 to 1V by cyclic voltammetry. When the performance of the product was abnormal or under other appropriate conditions, more cycles were performed. After the electrode activation was completed, the electrodeposition operation was performed immediately. With CFME as the working electrode, platinum wire as the counter electrode, and Hg / HgSO4 as the reference electrode, the deposition potential was -0.28 V and the deposition time was 120 s in the anhydrous ethanol solution supporting electrolyte configured in the above (1) by constant potential method. The deposited CFME-dAg was rinsed with pure water several times, dried at room temperature, and stored in a dark place;

[0067] (3) Electrical enrichment of carotene aldehyde molecules: Select pH 7.0 PBS as the supporting electrolyte, and use this electrolyte to dilute the carotene aldehyde stock solution (ethanol solution). After mixing, transfer it to the detection cell, use platinum wire as the counter electrode, Ag / AgCl as the reference electrode, and the CFME-dAg prepared in step (2) as the working electrode to construct a detection system. The carotene aldehyde molecules in the solution are electrically driven to adsorb and enrich by setting 0V and maintaining the potential for 10 minutes;

[0068] (4) Quantitative detection of carotene: Place the CFME-dAg after step (3) under a confocal microscope, select a 10× lens, a 532nm laser, and adjust the laser power to 1.0mW to record the Raman signal of carotene on the microelectrode surface. Compare the Raman signal strength, signal peak position and ratio of each signal peak of carotene at a potential of 0 to -1.0V, and then qualitatively analyze the carotene;

[0069] (5) The CFME-dAg that has been enriched in step (3) at a potential of 0 V is placed under a 10× confocal microscope with a power of 1.0 mW and a laser of 532 nm. Raman signals are collected 5 times at each point and the average value is taken. The concentration of carotenal is quantified by the intensity change of the Raman signal.

[0070] Example 6

[0071] The principle of preparing microelectrodes by organic phase electrodeposition and detecting carotene aldehyde by SERS in Example 1 is illustrated as follows: Figure 1 shown.

[0072] The SEM images, EDS and mapping images of the CFME-dAg prepared at different deposition times in Example 1 are recorded in Figure 2 middle.

[0073] For the blank CFME in the examples, 1 mM silver ions in aqueous solution and 10 mM electrodeposited CFME-dAd in ethanol solution were subjected to scanning electron microscopy. The obtained scanning electron micrographs are recorded in Figure 3 In, it is recorded as Figure 3 a, b; SEM images of CFME-dAg electrodeposited with 10 mM silver ions in ethanol solution in Example 3 Figure 3 In, it is recorded as Figure 3 c,d.

[0074] The CFME-dAg prepared at different deposition times in Example 1 was observed under a dark field microscope, and the scattering spectra of the prepared silver nanoparticles were recorded at Figure 4 In, it is recorded as Figure 4 a. The CFME-dAg electrodeposited at different silver ion concentrations in Example 1 was observed under a dark field microscope, and the scattering spectra of the obtained silver ion nanoparticles were recorded in Figure 4 In, it is recorded as Figure 4 b, SERS images of two carotenoids on the CFME-dAg surface under applied potential conditions were recorded as follows: Figure 4 c, SERS images of carotene on CFME-dAg at different deposition times are denoted as Figure 4 d.

[0075] SERS signals were recorded for different concentrations of carotene in Example 1 with and without potential applied to CFME-dAg. Figure 5 middle.

[0076] The CFME-dAg obtained by electrodeposition in 0.5 mM silver ion ethanol solution in Example 2 was observed by scanning electron microscope and the SERS signal was recorded. The obtained scanning electron microscope image is recorded in Figure 6 In the figure, a is the scanning electron microscope image, and b is the recorded SERS signal image.

[0077] The SERS signals of CFME-dAg electrodeposited with 10 mM silver ions in ethanol solution in Example 3 for detecting carotene and the comparison with electrodes prepared with other electrolytes are recorded in Figure 7 middle.

[0078] For Examples 1, 4 and 5, the SERS signals of carotene aldehyde produced by CFME-dAg at different deposition potentials in 1 mM silver ion ethanol solution electrolyte were recorded, and the obtained SERS signal graphs were recorded in Figure 8 middle.

[0079] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An application of an organic phase electrodeposition silver microelectrode for detecting carotene, characterized in that: The following steps are included: Prepare carotene aldehyde stock solution: dilute the carotene aldehyde stock solution with electrolyte solution, mix well and transfer to the detection cell; Construction of detection system: Platinum wire was used as the counter electrode, Ag / AgCl was used as the reference electrode, and CFME-dAg prepared by electrodeposition was used as the working electrode to construct the detection system; Quantitative detection of carotene: The constructed detection system was placed under a confocal microscope, a 10× lens and a 532nm laser were selected, and different laser powers were adjusted to record the Raman signal of carotene on the surface of the microelectrode; the Raman signal strength of carotene at different potentials, the position of the signal peaks and the ratio between the signal peaks were compared, and then the carotene was qualitatively and quantitatively analyzed; Calculation of carotene concentration: Carotene molecules were electro-enriched on the CFME-dAg surface at the optimal potential, the microelectrode was placed under a 10× confocal microscope, the optimal power laser 532nm was selected, and the Raman signal was collected 5 times at each point to take the average value, and the concentration of carotene was quantified by the intensity change of the Raman signal; Set 0V and maintain for 5-20 min to electrically drive the adsorption and enrichment of carotene molecules in the solution; The method for preparing the organic phase electrodeposition silver microelectrode for detecting carotenal comprises preparing an electrolyte: dissolving silver nitrate in anhydrous ethanol to obtain an electrodeposition electrolyte containing silver ions; Preparation of SERS active microelectrodes by electrodeposition: The carbon fiber microelectrodes are strictly cleaned, dried, and then electrochemically activated, followed by electrodeposition. The electrodeposition electrolyte prepared in the prepared electrolyte is used in the electrodeposition. After the electrodeposition is completed, the microelectrodes are rinsed and dried to obtain SERS active microelectrodes.

2. The use according to claim 1, characterized in that: In the prepared electrolyte, the concentration of silver ions in the electrodeposition electrolyte is 0.5~10 mM.

3. The use according to claim 1, characterized in that: In the prepared electrolyte, the concentration of silver ions in the electrodeposition electrolyte is 1 mM.

4. The use according to claim 1, characterized in that: In the electro-deposition to prepare the SERS active microelectrode, the electro-deposition selected deposition potential is -0.6~-0.1V.

5. The use according to claim 1, characterized in that: In the preparation of the SERS active microelectrode by electro-deposition, the deposition potential selected by the electro-deposition is -0.28~-0.1V.

6. The use according to claim 1, characterized in that: In the electro-deposition to prepare the SERS active microelectrode, the electro-deposition selected deposition potential is -0.164 V.

7. The use according to claim 1, characterized in that: Set 0V and maintain for 10min to electrically drive the adsorption and enrichment of carotene molecules in the solution.

Images