Portable self-powered photochromic length visual detection device and preparation and application thereof

Abstract

The invention provides a portable self-powered photoelectrochromic length visualization detection device. The portable self-powered photoelectrochromic length visualization detection device comprises a semiconductor substrate, a detection area and a visual visualization area, wherein the detection area and the visual visualization area are arranged on the semiconductor substrate; the detection area is modified with a photocatalytic material; the visual visualization area is plated with a color-changing material; the fading length of the visual visualization area can be changed by photo-induced electrons generated by the reaction of the detection area modified photocatalytic material and an object to be detected. According to the device, the photocatalytic material is excited by light to oxidize the to-be-detected object, and electrons are provided for the photocatalytic material, so that the color change length of the visual visualization area is positively correlated with the concentration of the to-be-detected object. The concentration of the to-be-detected object can be directly obtained by observing the color changing length of the visual visualization area. Furthermore, the limitation of time and space and the error caused by operating equipment are avoided; in the detection process, an external power supply and an electrode are not needed, indoor and outdoor photoelectrochemical detection is achieved through illumination, the use mode is flexible, and the method has the advantages of being low in preparation cost, wide in application, convenient and fast to use and good in universality.

Description

Technical Field

[0001] The invention relates to the technical field of electrochromic visualization sensing, and in particular to a portable self-powered photoelectric electrochromic length visualization detection device and a preparation and application thereof. Background Art

[0002] Visual detection technology has many advantages. It can directly observe the relevant information of the detection object through the naked eye or mobile phones. The detection of the sensor does not rely on the use of external large instruments. It is very conducive to the rapid detection of various detection objects and is an ideal platform for biochemical sensing. Photoelectrochemical sensing (PEC) is a detection technology developed based on the electrochemical signal generated under light. It uses the photoelectric conversion characteristics of photoelectrically active substances to determine the concentration of the detection object, replacing the traditional electrochemical workstation. The generated photocurrent can be quantified by observing the change in color change by the naked eye, which is more convenient.

[0003] At present, most PEC visualization devices are generally based on the signal readout of PEC visualization luminescence intensity or color change, which may be limited by environmental factors, and may also cause certain errors due to personal differences in operators or different readout devices. Therefore, it is particularly necessary to develop a portable photoelectric chromatic visualization length detection device and method.

[0004] The Chinese invention patent with announcement number CN117825466A discloses a visualization detection device for regulating electrochemical luminescence length by enzyme-catalyzed electrodeposition and a method for detecting hydrogen peroxide concentration. However, the device requires the setting of a workstation and relies on modifying the enzyme catalyst in the detection area to catalyze the formation of precipitation between the object to be detected and the substrate to increase impedance, thereby changing the luminescence length of the strip in the visual visualization area, measuring the luminescence length of the strip, and calculating the concentration of the object to be detected. It requires a large number of electronic equipment such as chemical workstations and electrodes, etc., has poor portability, limited scope of application, and is not conducive to promotion and on-site operation. Summary of the invention

[0005] The purpose of the present invention is to solve the above-mentioned technical problems and to provide a portable self-powered photoelectric electrochromic length visualization detection device. The portable self-powered photoelectric electrochromic length visualization detection device is convenient for detection and does not require a large number of electronic equipment such as chemical workstations and electrodes. Another purpose of the present invention is to provide the preparation of the device. Another purpose of the present invention is to provide the application of the device.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A portable self-powered photoelectrochromic length visualization detection device comprises a semiconductor substrate and a detection area and a visual visualization area arranged on the semiconductor substrate; the detection area is modified with a photocatalytic material; the visual visualization area is plated with a color-changing material; photogenerated electrons generated by the reaction between the photocatalytic material modified in the detection area and an object to be detected can change the fading length of the visual visualization area.

[0008] The portable self-powered photoelectrochromic length visualization detection device of the present invention comprises a semiconductor substrate and a detection area and a visual visualization area arranged on the semiconductor substrate. Under light conditions, the photocatalytic material is excited to generate hole-electron pairs, and the electrons on its valence band are excited to the conduction band and then transmitted to the semiconductor substrate, thereby converting the light signal into a photocurrent signal as an output signal. When the photocatalytic material is stimulated by light, the object to be detected is oxidized, acting as a hole scavenger to provide electrons for the photocatalytic material, reducing the recombination of electron-hole pairs and enhancing the photocurrent. Therefore, under the condition that other conditions remain unchanged, the length of the color change in the visual visualization area is positively correlated with the concentration of the object to be detected. The concentration of the object to be detected can be directly obtained by observing the difference in the color change length of the visual visualization area of ​​the device with the naked eye.

[0009] Furthermore, the detection area is connected to the visual visualization area, and the detection area is a strip structure composed of strips of equal width.

[0010] Preferably, the strips of equal width are arranged in a straight line on the semiconductor substrate;

[0011] Or, the equal-width strips are arranged in a curved shape on the semiconductor substrate;

[0012] Or, the equal-width strips are arranged at intervals in a concave-convex shape on the semiconductor substrate, and the intervals are greater than 2 mm;

[0013] Alternatively, the equal-width strips are arranged in a spiral shape on the semiconductor substrate, and the interval between adjacent spirals is greater than 2 mm.

[0014] Furthermore, the visual visualization area is electroplated with a color-changing material, Prussian blue; the photocatalytic material is cadmium sulfide; and the semiconductor substrate is an ITO substrate.

[0015] Furthermore, the size of the detection area is 5-20mm×5-20mm, the strips of the visual visualization area are continuous strips of equal width, which are arranged at intervals in a concave-convex shape on the substrate, and the intervals are equal to 1-5mm; the width of the equal-width strips is 0.5-2.5mm, and the total length is 50-200mm.

[0016] Preferably, the detection area is a square detection area with a size of 10 mm×10 mm.

[0017] Preferably, the visual visualization areas are arranged at intervals in a concave-convex shape on the semiconductor substrate, and the intervals are equal to 3 mm; the width of the equal-width strips is 1.5 mm, and the total length is 100 mm.

[0018] The present invention also provides a method for preparing the above-mentioned portable self-powered photoelectrochromic length visualization detection device, comprising the following steps:

[0019] P1. Take a semiconductor substrate and etch out interconnected detection areas and visualization areas;

[0020] P2. Coating a photocatalytic material on the detection area; coating Prussian blue on the visualization area to obtain a portable self-powered photoelectrochromic length visualization detection device.

[0021] Furthermore, in step P2, the Prussian blue is plated on the visualization area by electroplating, the electroplating is constant voltage electroplating, the electroplating voltage is 0.1-0.5V; the electroplating time is 50-100s; the electroplating solution consists of 1-10mM FeCl3·6H2O, 1-10mM k3[Fe(CN)6] and 1-10mM HCl.

[0022] Furthermore, before etching the semiconductor substrate in step P1, the semiconductor substrate needs to be cleaned to remove impurities or other organic pollutants thereon.

[0023] Furthermore, before coating the photocatalytic material on the detection area in step P2, a fixing agent for the photocatalytic material needs to be coated between the semiconductor substrate and the photocatalytic material.

[0024] Preferably, the fixing agent of the photocatalytic material is chitosan.

[0025] Furthermore, in step P2, the electroplating uses a chemical workstation to electroplate Prussian blue in the visual visualization area and dry it; the counter electrode is a platinum sheet electrode, and the reference electrode is an Ag / AgCl electrode. The counter electrode is a platinum sheet electrode, and the reference electrode is an Ag / AgCl electrode.

[0026] The present invention also provides the use of the portable self-powered photoelectrically induced chromic length visualization detection device in detecting ascorbic acid concentration for non-treatment purposes or in preparing an ascorbic acid kit.

[0027] The present invention provides the above-mentioned portable self-powered photoelectrochromic length visualization method for detecting ascorbic acid concentration, comprising the following steps:

[0028] S1. constructing a standard curve of the relationship between the color change length of the visual visualization zone 2 and the ascorbic acid concentration using the above-mentioned portable self-powered photoelectrochromic length visualization detection device;

[0029] S2. Adding an ascorbic acid solution of the concentration to be tested dropwise to the detection area;

[0030] S3. After the reaction is irradiated with ultraviolet light, the color change length of the visual visualization area is measured, and the concentration of the ascorbic acid to be detected is calculated using the standard curve in S1.

[0031] Preferably, the ultraviolet light irradiation reaction is irradiation with a ultraviolet light with a power of 3-10W and a wavelength of 405nm for 10-20min.

[0032] Furthermore, in step S1, the method for constructing the standard curve is: preparing ascorbic acid solutions of different known concentrations, measuring the fading length of the visual visualization area under the ascorbic acid solutions of different known concentrations according to the method described in S2-S3, and drawing the standard curve.

[0033] Furthermore, the amount of the substance to be detected is 10-30 μL, and the concentration is 10-10 5 μM.

[0034] The beneficial effects of the present invention are as follows:

[0035] (1) The present invention is a portable visual self-powered detection device that detects the concentration of the object to be detected based on the catalytic oxidation of the object to be detected by photocatalytic materials to adjust the fading length of the color-changing material, rather than based on the signal readout of the visualized luminous intensity or material color change; the present invention detects the concentration of the object to be detected based on the change in the color change length of the visual visualization area, which is clearer and avoids the limitations of time and space and the errors caused by operating equipment.

[0036] (2) The present invention does not require an external power supply during the detection process. The detection device itself provides energy for its detection process. There is no need for a three-electrode system. It can realize both indoor photoelectrochemical detection and outdoor photoelectrochromic detection, thereby achieving the purpose of timely detection. It has a flexible usage mode and has the characteristics of low preparation cost, wide application, convenience, etc.

[0037] (3) The portable self-powered photochromic length visualization detection device of the present invention realizes the detection of AA concentration. In the photoelectric mode, the concentration of AA can be detected within 10-10 5 In the μM concentration range, the logarithm of AA concentration (log CAA) and the length of fading of the Prussian blue band showed a good linear relationship.

[0038] (4) The present invention is universal and can not only detect the AA concentration by observing the change in the length of the stripe fading in the visual visualization area, but also detect the concentration of specific substances by constructing various chemical and biological sensing mechanisms in the detection area. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the structure of the working electrode in the portable self-powered photoelectrochromic length visualization detection device of the present invention; the meanings of the markings in the figure are as follows: 1 is the detection area; 2 is the visual visualization area 2.

[0040] Figure 2 Diagram of the detection mechanism of the constructed portable self-powered photoelectrochromic length visualization sensor.

[0041] Figure 3 This is a scanning electron microscope image of the photocatalytic material cadmium sulfide.

[0042] Figure 4 This is a graph showing the color change length of the strip in the visual visualization area of ​​the device as the concentration of ascorbic acid is detected.

[0043] Figure 5 The standard curve diagram of the relationship between the color change length of the constructed band and the ascorbic acid concentration.

[0044] Figure 6 This is a comparison chart of the photocurrent of cadmium sulfide and Co-N-TiO2 / 3DGH.

[0045] Figure 7 This is a comparison chart of the effects of cadmium sulfide and Co-N-TiO2 / 3DGH. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0047] Example 1

[0048] Reference Figure 1 The present embodiment provides a portable self-powered photoelectrochromic length visualization detection device, comprising a semiconductor substrate and a detection area 1 and a visual visualization area 2 arranged on the semiconductor substrate; the detection area 1 is modified with a photocatalytic material; the visual visualization area 2 is plated with a color-changing material; the detection area 1 and the visual visualization area 2 are connected, and the detection area 1 is a strip structure composed of equal-width strips; the photogenerated electrons generated by the reaction of the photocatalytic material modified in the detection area 1 with the object to be detected can change the fading length of the visual visualization area 2.

[0049] As an optional solution, the equal-width strips are arranged in a straight line on the semiconductor substrate; or, the equal-width strips are arranged in a curve on the semiconductor substrate; or, the equal-width strips are arranged in a concave-convex shape at intervals on the semiconductor substrate, and the intervals are greater than 2mm; or, the equal-width strips are arranged in a spiral shape on the semiconductor substrate, and the intervals between adjacent spirals are greater than 2mm. Figure 1 That is, the concave-convex spacing setting.

[0050] The portable self-powered photochromic length visualization detection device of the present invention comprises a semiconductor substrate and a detection area 1 and a visual visualization area 2 arranged on the semiconductor substrate. Under light conditions, the photocatalytic material is excited to generate hole-electron pairs, and the electrons on its valence band are excited to the conduction band and then transmitted to the semiconductor substrate, thereby converting the light signal into a photocurrent signal as an output signal. When the photocatalytic material is stimulated by light, the object to be detected is oxidized, acting as a hole scavenger to provide electrons for the photocatalytic material, reducing the recombination of electron-hole pairs and enhancing the photocurrent. Therefore, under the condition that other conditions remain unchanged, the length of the color change of the visual visualization area 2 is positively correlated with the concentration of the object to be detected. The concentration of the object to be detected can be directly obtained by observing the difference in the color change length of the visual visualization area 2 of the device with the naked eye.

[0051] As an optional solution, the visual visualization area 2 is electroplated with a color-changing material, Prussian blue; the photocatalytic material is cadmium sulfide; and the semiconductor substrate is an ITO substrate, which can detect organic substances such as ascorbic acid.

[0052] like Figure 2 Under the irradiation of ultraviolet light, the photocatalytic material is excited to produce hole-electron pairs, and the electrons on its valence band are excited to the conduction band and then transmitted to the ITO substrate, thereby converting the light signal into a photocurrent signal as an output signal. The valence band point of CdS is greater than +2.5eV, and the oxidation potential of ascorbic acid is +0.153eV. When CdS is stimulated by light, ascorbic acid is easily oxidized by holes to dehydroascorbic acid. AA acts as a hole scavenger, providing electrons for CdS, reducing the recombination of electron-hole pairs, and enhancing the photocurrent. The length of the color change in the visual visualization area 2 is positively correlated with the concentration of ascorbic acid to be detected, so ascorbic acid can be determined.

[0053] like Figure 1, the dimensions of the portable self-powered photoelectrochromic length visualization detection device can meet the following requirements: the dimensions of the detection area 1 are 5-20mm×5-20mm, the strips of the visual visualization area 2 are continuous equal-width strips, which are arranged at intervals in a concave-convex shape on the substrate, and the intervals are equal to 1-5mm; the width of the equal-width strips is 0.5-2.5mm, and the total length is 50-200mm. In this embodiment, the detection area 1 is a square detection area with a dimension of 10mm×10mm; the visual visualization area 2 is arranged in a concave-convex shape on the semiconductor substrate, and the intervals are equal to 3mm; the width of the equal-width strips is 1.5mm, and the total length is 100mm.

[0054] Example 2

[0055] The present invention also provides a method for preparing the portable self-powered photoelectrochromic length visualization detection device of the above-mentioned embodiment 1, comprising the following steps:

[0056] P1. Take the semiconductor substrate and etch out the interconnected detection area 1 and visualization area 2;

[0057] In step P1, before etching the semiconductor substrate, the semiconductor substrate needs to be cleaned, such as ultrasonically cleaning in acetone, ethanol and distilled water in sequence, to remove impurities or other organic pollutants thereon.

[0058] P2. A fixing agent for the photocatalytic material is coated between the semiconductor substrate and the photocatalytic material. Preferably, the fixing agent for the photocatalytic material is chitosan; and then the photocatalytic material is coated on the detection area 1, such as Figure 3 It is a scanning electron microscope image of the photocatalytic material cadmium sulfide; Prussian blue is plated on the visual visualization area 2 to obtain a portable self-powered photoelectrochromic length visualization detection device.

[0059] Among them, the step P2 of plating Prussian blue on the visual visualization area 2 is an electroplating method, the electroplating is a constant voltage electroplating, the electroplating voltage is 0.1-0.5V; the electroplating time is 50-100s; the electroplating solution composition is 1-10mM FeCl3·6H2O, 1-10mM k3[Fe(CN)6] and 1-10mM HCl; the electroplating uses a chemical workstation to electroplate Prussian blue on the visual visualization area 2 and dry it; the counter electrode is a platinum sheet electrode, and the reference electrode is an Ag / AgCl electrode. The counter electrode is a platinum sheet electrode, and the reference electrode is an Ag / AgCl electrode.

[0060] Specifically, the experimental operation is as follows:

[0061] First, pre-treat the semiconductor substrate ITO conductive glass and cut the ITO into 3*4cm 2The uniform-sized flakes were then ultrasonically cleaned with acetone, distilled water, and ethanol, and dried with nitrogen. Figure 1 The pattern shown is then presented on the clean ITO by laser etching with a pattern with functional areas, including a detection area 1 (10mm*10mm) and a visual visualization area 2 (1.5mm in width and 100mm in length).

[0062] Prussian blue was electroplated on visual visualization area 2 using a chemical workstation and dried to fix it on visual visualization area 2. The counter electrode was a platinum electrode, the reference electrode was an Ag / AgCl electrode, the color-changing material was a Prussian blue solution, and the electroplating solution composition was 5mM FeCl3·6H2O, 5mM k3[Fe(CN)6], and 5mM HCl. The method used was a constant voltage method, the electroplating time was 75s, and the voltage was 0.3V; an appropriate amount of chitosan was taken as a fixative in detection area 1, dried, and then 20μl of cadmium sulfide was added and dried to obtain a portable self-powered photoelectrochromic length visualization detection device.

[0063] Example 3

[0064] The present invention provides the above-mentioned portable self-powered photoelectrochromic length visualization method for detecting ascorbic acid concentration, comprising the following steps:

[0065] S1. Use the above-mentioned portable self-powered photoelectrochromic length visualization detection device to construct a standard curve of the relationship between the color change length of the visual visualization area 2 and the ascorbic acid concentration; specifically, configure ascorbic acid solutions of different known concentrations (0; 10 μM; 100 μM; 10 3 μM; 10 4 μM; 10 5 μM), and measure the fading length of visual visualization zone 2 under ascorbic acid solutions of different known concentrations according to the method described in S2-S3, and draw a standard curve, such as Figure 5 shown.

[0066] S2. Add an ascorbic acid solution of the concentration to be tested to the detection zone 1;

[0067] S3. After the ultraviolet light irradiation reaction, the color change length of the visual visualization area 2 is measured, and the concentration of the ascorbic acid to be detected is calculated using the standard curve in S1. As an optional solution, the ultraviolet light irradiation reaction is irradiated with a 5W ultraviolet light with a wavelength of 405nm for 15 minutes.

[0068] Specifically, the experimental steps are as follows:

[0069] Prepare a 0.1M potassium chloride solution with a pH value of 6.8, and prepare an ascorbic acid solution of the concentration to be tested; take 20 ml of potassium chloride solution and 20 μl of ascorbic acid solution, mix the two and shake well; take an appropriate amount of the mixed solution and drop it on the detection area 1 of the ITO slide modified with the photocatalytic material and Prussian blue; use a 5W purple light with a wavelength of 405nm to irradiate for 15 minutes. After the reaction, measure the fading length of the strip in the visual visualization area 2, and conduct multiple experiments, record the data, and draw a standard curve of the relationship between the fading length of the strip and the ascorbic acid concentration. The logarithmic value of the AA concentration (log CAA) shows a good linear relationship with the length of the Prussian blue strip fading. Theoretically, the higher the AA concentration, the longer the strip fades. In this embodiment, the preferred amount of the object to be detected is 10-30 μL, and the concentration is 10-10 5 μM.

[0070] Test Example 1 Comparison of photocurrent and detection effects between CdS and Co-N-TiO2 / 3DGH

[0071] 1. Test Method

[0072] The photoelectric material in Implementation 2 was replaced with Co-N-TiO2 / 3DGH, and other conditions remained unchanged. The photocurrent was tested and compared with the photocurrent of cadmium sulfide.

[0073] 2. Test results

[0074] like Figure 6 It can be seen that the photocurrent of cadmium sulfide is much larger than that of Co-N-TiO2 / 3DGH. Then, the sensing detection is performed. Under the same conditions, 1mM ascorbic acid is used for detection. Figure 7 As shown, the experimental results show that the strip color change length of CdS detection is longer and the color change is clear, and the detection effect is better than Co-N-TiO2 / 3DGH.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the solution. 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 solution of the present invention can be modified or replaced by equivalents based on the understanding of the present solution without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A portable self-powered photoelectrochromic length visualization detection device, characterized in that: The invention comprises a semiconductor substrate and a detection area (1) and a visual visualization area (2) arranged on the semiconductor substrate; the detection area (1) is modified with a photocatalytic material; the visual visualization area (2) is plated with a color-changing material; and the photogenerated electrons generated by the reaction between the photocatalytic material modified in the detection area (1) and an object to be detected can change the fading length of the visual visualization area (2).

2. The portable self-powered photoelectrochromic length visualization detection device according to claim 1, characterized in that: The detection area (1) is connected to the visual visualization area (2), and the detection area (1) is a strip structure composed of strips of equal width.

3. The portable self-powered photoelectrochromic length visualization detection device according to claim 1, characterized in that: The visual visualization area (2) is electroplated with a color-changing material, Prussian blue; the photocatalytic material is cadmium sulfide; and the semiconductor substrate is an ITO substrate.

4. The portable self-powered photoelectrochromic length visualization detection device according to claim 3, characterized in that: The size of the detection area (1) is 5-20 mm×5-20 mm, and the strips of the visual visualization area (2) are continuous strips of equal width, which are arranged at intervals in a concave-convex shape on the substrate, and the intervals are equal to 1-5 mm; the width of the equal width strips is 0.5-2.5 mm, and the total length is 50-200 mm.

5. The method for preparing the portable self-powered photoelectrochromic length visualization detection device according to any one of claims 1 to 4, characterized in that: The steps include: P1. Take a semiconductor substrate and etch out interconnected detection areas (1) and visualization areas (2); P2. Coating a photocatalytic material on the detection area (1); The visualization area (2) is plated with Prussian blue to obtain a portable self-powered photoelectrochromic length visualization detection device.

6. The method for preparing the portable self-powered photoelectrochromic length visualization detection device according to claim 5, characterized in that: In step P2, the Prussian blue is plated on the visualization area (2) by electroplating, the electroplating is constant voltage electroplating, the electroplating voltage is 0.1-0.5V; the electroplating time is 50-100s; the electroplating solution composition is 1-10mMFeCl3·6H2O, 1-10mM k3[Fe(CN)6] and 1-10mM HCl.

7. Use of the portable self-powered photoelectrochromic length visualization detection device according to any one of claims 1 to 4 in detecting ascorbic acid concentration for non-therapeutic purposes or in preparing an ascorbic acid kit.

8. A portable self-powered photoelectrochromic length visualization method for detecting ascorbic acid concentration, characterized in that: The following steps are involved: S1. Using the portable self-powered photoelectrochromic length visualization detection device described in claims 1-4 to construct a standard curve of the relationship between the color change length of the visual visualization area (2) and the ascorbic acid concentration; S2. Adding an ascorbic acid solution of the concentration to be tested dropwise to the detection area (1); S3. After the reaction is irradiated with ultraviolet light, the color change length of the visual visualization area (2) is measured, and the concentration of the ascorbic acid to be detected is calculated using the standard curve in S1.

9. The method for detecting ascorbic acid concentration by portable self-powered photoelectrochromic length visualization according to claim 8, characterized in that: In step S1, the method for constructing the standard curve is: preparing ascorbic acid solutions of different known concentrations, measuring the fading length of the visual visualization area (2) under the ascorbic acid solutions of different known concentrations according to the method described in S2-S3, and drawing the standard curve.

10. The portable self-powered photoelectrochromic length visualization method for detecting ascorbic acid concentration according to claim 8, characterized in that: The amount of the substance to be detected is 10-30 μL, and the concentration is 10-10 5 μM.

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