CUV2O6-BASED PHOTOELECTRIC SENSOR AND APPLICATION THEREOF IN DETECTION OF ARGININE

Abstract

A CuV.sub.2O.sub.6-based photoelectric sensor is prepared through the following steps: acquiring a CuV.sub.2O.sub.6 thin film through a direct-current reactive magnetron co-sputtering method; and loading an 8-hydroxyquinoline solution on the CuV.sub.2O.sub.6 thin film through a spin-coating method to acquire an 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor. The 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor has a good anti-interference capability in the detection of arginine; it is easy to realize the low-cost mass production of CuV.sub.2O.sub.6 photoelectrodes through a developed direct-current reactive magnetron sputtering coating method; and a sensor device is low in cost, simple, portable, and easy to use, and has an application value in food safety and health and hygiene detection.

Claims

1. A CuV.sub.2O.sub.6 -based photoelectric sensor, wherein the CuV.sub.2O.sub.6-based photoelectric sensor is prepared through by a method comprising the following steps: 1. acquiring a CuV.sub.2O.sub.6 thin film through a direct-current reactive magnetron co-sputtering method; and 2. loading an 8-hydroxyquinoline solution on the CuV.sub.2O.sub.6 thin film through a spin-coating method to acquire an 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor.

2. The CuV.sub.2O.sub.6 -based photoelectric sensor according to claim 1, wherein: step 1 comprises: installing a target and a substrate on a magnetron sputtering instrument starting pre-sputtering through the direct-current reactive magnetron co-sputtering method, wherein a chamber atmosphere and pressure of the magnetron sputtering instrument are controlled, and power of the target and a temperature of the substrate are set; opening a substrate baffle to start deposition after glow stabilizes; taking out a sample after the deposition is ended; calcining the sample in an air atmosphere to acquire the CuV.sub.2O.sub.6 thin film; and step 2 comprises: placing the CuV.sub.2O.sub.6 thin film on a spin coater; and loading the 8-hydroxyquinoline solution on the CuV.sub.2O.sub.6 thin film through the spin-coating method to acquire the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor.

3. The CuV.sub.2O.sub.6 -based photoelectric sensor according to claim 2, wherein, the target comprises metal Cu and metal V, a sputtering power source is a direct-current power source, the chamber atmosphere of the magnetron sputtering instrument is a mixture of argon and oxygen, a sputtering mode is co-sputtering of the metal Cu and the metal V, and the substrate is Fluorine-doped Tin Oxide (FTO) glass.

4. The CuV.sub.2O.sub.6 -based photoelectric sensor according to claim 3, wherein, a power of the metal Cu is 10-50 W, a power of the metal V is 100-500 W, pre-sputtering pressure is 0.5-2.5 Pa, the temperature of the substrate is 100-400° C., a rotating speed of a substrate holder is 5-30 r/min, a pre-sputtering time is 300-1,200 s, a deposition time is 1,000-6,000 s, a calcination temperature is 200-550° C., and a calcination time is 0.5-2 h.

5. The CuV.sub.2O.sub.6 -based photoelectric sensor according to claim 2, wherein, the 8-hydroxyquinoline solution is prepared through the following steps: dissolving 8-hydroxyquinoline in ethanol to prepare a solution with a concentration of 100-1,400 mmol/L, and mixing the prepared solution with Nafion with a mass fraction of 1-10% according to a volume ratio of 9:1 to acquire the 8-hydroxyquinoline solution.

6. The CuV.sub.2O.sub.6 -based photoelectric sensor according to claim 5, wherein, a dropping amount of the 8-hydroxyquinoline solution is 10-40 μL, and the spin coater rotates at a rotating speed of 500-2,000 r/min for 9-40 s.

7. A detection method, comprising the step of using the CuV.sub.2O.sub.6 -based photoelectric sensor according to claim 1 for detecting arginine in a sample to be tested.

8. The detection method according to claim 7, comprising: immersing the CuV.sub.2O.sub.6 -based photoelectric sensor in borate buffered saline containing arginine of different concentrations for incubation, and then taking out the CuV.sub.2O.sub.6 -based photoelectric sensor; testing an electrode photocurrent of the CuV.sub.2O.sub.6 -based photoelectric sensor with a three-electrode system; drawing a fitting working curve of photocurrent density and a concentration of the arginine; and detecting the arginine in the sample to be tested with a standard addition method.

9. The detection method according to claim 8, wherein an incubation time is 10-120 min.

10. The detection method according to claim 8, wherein the electrode photocurrent of the CuV.sub.2O.sub.6-based photoelectric sensor is tested with the three-electrode system under a voltage of 0.9-1.6V vs RHE.

11. The CuV.sub.2O.sub.6 -based photoelectric sensor according to claim 1, wherein the 8-hydroxyquinoline solution is prepared through the following steps: dissolving 8-hydroxyquinoline in ethanol to prepare a solution with a concentration of 100-1,400 mmol/L, and mixing the prepared solution with Nafion with a mass fraction of 1-10% according to a volume ratio of 9:1 to acquire the 8-hydroxyquinoline solution.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a schematic diagram of a mechanism of an 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor according to the present invention;

[0027] FIG. 2 is a scanning electron microscope (SEM) image of a CuV.sub.2O.sub.6 thin film prepared according to Embodiment 1;

[0028] FIG. 3 is an X-ray diffraction (XRD) pattern of the CuV.sub.2O.sub.6 thin film prepared according to Embodiment 1;

[0029] FIG. 4 shows visible-light absorption spectrograms of a CuV.sub.2O.sub.6 thin film, a 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor prepared according to Embodiment 1, and the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor prepared according to Embodiment 1 after incubation in arginine;

[0030] FIG. 5 shows infrared spectrograms of a CuV.sub.2O.sub.6 thin film, a 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor, and the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor after incubation in arginine;

[0031] FIG. 6 is a comparison diagram of photocurrent stability of an 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor and an 8-hydroxyquinoline-modified CuO photoelectric sensor;

[0032] FIG. 7 is a diagram of a photoelectric signal detected after an 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor is incubated in borate buffered saline containing arginine of different concentrations;

[0033] FIG. 8 is a diagram showing a linear relationship between a base-10 logarithm of photocurrent density and the concentration of arginine after an 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor is incubated in arginine of different concentrations; and

[0034] FIG. 9 is a diagram showing response of a photoelectric signal of an 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor to different amino acids.

DETAILED DESCRIPTION

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the embodiments described are merely some but not all embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments derived by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Unless otherwise specified, devices and reagents used in the present invention are conventional commercially available products in the art. In the following embodiments, the used reagents all were analytical reagents and water used in tests was ultrapure water (conductivity ≤0.4 μc/cm.sup.2).

[0036] As shown in FIG. 1, the present invention provides a CuV.sub.2O.sub.6 -based photoelectric sensor. The CuV.sub.2O.sub.6 -based photoelectric sensor is prepared through the following steps: a CuV.sub.2O.sub.6 thin film is acquired through a direct-current reactive magnetron co-sputtering method; and an 8-hydroxyquinoline solution is loaded on the CuV.sub.2O.sub.6 thin film through a spin-coating method to acquire an 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor.

[0037] Specific implementation steps are as follows.

[0038] Pre-sputtering is started through the direct-current reactive magnetron co-sputtering method after a target and a substrate are installed on a magnetron sputtering instrument, a chamber atmosphere and pressure of the magnetron sputtering instrument are controlled, and the power of the target and the temperature of the substrate are set; a substrate baffle is opened to start deposition after glow stabilizes; and a sample is taken out after deposition is ended and calcined in an air atmosphere to acquire the CuV.sub.2O.sub.6 thin film. The acquired CuV.sub.2O.sub.6 thin film is placed on a spin coater; and the 8-hydroxyquinoline solution is loaded on the CuV.sub.2O.sub.6 thin film through the spin- coating method to acquire the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor.

[0039] In the following embodiment, preferably, the target includes metal Cu and metal V, a sputtering power source is a direct-current power source, the chamber atmosphere of the magnetron sputtering instrument is a mixture of argon and oxygen, a sputtering mode is co-sputtering of Cu and V, and the substrate is FTO glass. Further preferably, the power of the metal Cu is 10-50 W, the power of the metal V is 100-500 W, pre-sputtering pressure is 0.5-2.5 Pa, the temperature of the substrate is 100-400° C., a rotating speed of a substrate holder is 5-30 r/min, a pre-sputtering time is 300-1,200 s, a deposition time is 1,000-6,000 s, a calcination temperature is 200-550° C., and a calcination time is 0.5-2 h.

[0040] In the following embodiment, the 8-hydroxyquinoline solution is prepared through the following steps: 8-hydroxyquinoline is dissolved in ethanol to prepare a solution with the concentration of 100-1,400 mmol /L, and this solution is mixed with Nafion with the mass fraction of 1-10% according to the volume ratio of 9:1 to acquire the 8-hydroxyquinoline solution.

[0041] In the following embodiment, the 8-hydroxyquinoline solution is loaded on the CuV.sub.2O.sub.6 thin film at a dropping amount of 10-40 μL through the spin-coating method, and the spin coater rotates at the rotating speed of 500-2,000 r/min for 9-40 s.

[0042] For the use of the CuV.sub.2O.sub.6 -based photoelectric sensor according to the present invention, the photoelectric sensor has an obvious response to the detection of arginine, but no obvious response to other amino acids.

[0043] For the application of sensor, the following steps are specifically included: the photoelectric sensor is immersed in borate buffered saline (BBS, pH=9) containing arginine of different concentrations for incubation and then the photoelectric sensor is taken out. An electrode photocurrent of the sensor is tested with a three-electrode system. A fitting working curve of photocurrent density and the concentration of arginine is drawn. Arginine in a sample to be tested is detected with a standard addition method.

[0044] In the following embodiment, preferably, the photoelectric sensor is immersed in the borate buffered saline for incubation for 10-120 min. The electrode photocurrent of the sensor is tested with the three-electrode system under the voltage of 0.9-1.6V vs RHE.

[0045] In the present invention, the photoelectrochemical sensor for detecting arginine is prepared for the first time and thus the arginine can be detected accurately and efficiently. The sensor shows good photoelectrochemical response characteristics to arginine, and the base-10 logarithm of the photocurrent density has a good linear relationship with the concentration of arginine, thereby greatly improving the signal strength of a traditional electrochemical method.

Embodiment 1

[0046] A CuV.sub.2O.sub.6-based photoelectric sensor is prepared through the following steps.

[0047] (1) Pre-sputtering is started for 600 s through a direct-current reactive magnetron co-sputtering method after a target metal Cu and a target metal V are installed on a magnetron sputtering instrument, wherein a substrate is FTO glass, a sputtering mode is co-sputtering of Cu and V, a chamber atmosphere of the magnetron sputtering instrument is a mixture of argon and oxygen, and the following parameters are set: the power of the target Cu is 15 W, the power of the target V is 350W, the sputtering pressure is 1.2 Pa, the temperature of the substrate is 200° C., and the rotating speed of a substrate holder is 20 r/min. After glow stabilizes, a substrate baffle is opened to start deposition for 2,700 s. A sample is taken out after the deposition is ended and calcined at 450° C. for 1 h in an air atmosphere to acquire a CuV.sub.2O.sub.6 thin film.

[0048] (2) A 200 mmol/L 8-hydroxyquinoline-ethanol solution is mixed with Nafion with the mass fraction of 5% according to the volume ratio of 9:1 to acquire an 8-hydroxyquinoline solution. 20 μL of the prepared 8-hydroxyquinoline solution is loaded on the CuV.sub.2O.sub.6 thin film acquired in step (1) through a spin-coating method to acquire the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor, wherein a spin coater rotates at the rotating speed of 1,000 r/min for 18 s.

[0049] The surface morphology features and structure of the CuV.sub.2O.sub.6 thin film acquired in step (1) were analyzed through a scanning electron microscope (SEM) and an X-ray diffractometer (XRD). As shown in FIG. 2 and FIG. 3, it can be obviously seen from an SEM image of FIG. 2 that the prepared CuV.sub.2O.sub.6 was formed by densely packing linear particles. An XRD pattern of FIG. 3 showed that in addition to diffraction peaks (SnO.sub.2) of the FTO substrate, diffraction peaks of CuV.sub.2O.sub.6 may be clearly found.

[0050] The 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor acquired in step (2) was immersed in 0.1 mmol/L arginine-borate buffered saline (BBS, pH=9) for incubation for 10 minutes, then taken out, and rinsed with the borate buffered saline for three times.

[0051] The absorbance of the CuV.sub.2O.sub.6 thin film acquired in step (1), the absorbance of the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor acquired in step (2), and the absorbance of the 8-hydroxyquine-modified CuV.sub.2O.sub.6 photoelectric sensor acquired in step (2) after incubation in arginine were tested respectively with an ultraviolet-visible-near-infrared spectrophotometer (FIG. 4). It can be seen from FIG. 4 that the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor absorbed visible light after being incubated in an arginine solution, and the absorbance did not change greatly after the CuV.sub.2O.sub.6 thin film was loaded with 8-hydroxyquinoline and the sensor was incubated in the arginine solution.

[0052] Infrared spectrograms of the CuV.sub.2O.sub.6 thin film acquired in step (1), the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor acquired in step (2), and the 8-hydroxyquine-modified CuV.sub.2O.sub.6 photoelectric sensor acquired in step (2) after incubation in arginine were tested with an infrared analyzer (FIG. 5). It can be seen from FIG. 5 that extra peaks of the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor compared with the CuV.sub.2O.sub.6 thin film corresponded to infrared spectrum peaks of 8-hydroxyquinoline, which indicated that 8-hydroxyquinoline was effectively loaded on the surface of the CuV.sub.2O.sub.6 photoelectric sensor. After the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor was incubated in arginine, the infrared spectrum of the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor showed an extra peak obviously at the position of 1680 cm.sup.−1, and this peak may be assigned to a —NH.sub.2 group of arginine.

Experimental Example 1

[0053] The 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor prepared in Embodiment 1 was immersed in borate buffered saline (BBS, pH=9) containing arginine of different concentrations, i.e., 10 μmol/L, 20 μmol/L, 40 μmol/L, 100 μmol/L, 200 μmol/L, 400 μmol/L, 1,000 μmol/L, respectively for incubation for 10 min, then taken out and rinsed with borate buffered saline for three times. A photocurrent of the sensor was tested with a three-electrode system, a fitting working curve of the photocurrent density and the concentration of arginine was drawn, and then arginine in the sample to be tested was detected with a standard addition method.

[0054] 1. Stability of 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor

[0055] Photocurrents of the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor and an 8-hydroxyquinoline-modified CuO photoelectric sensor were tested for 30 min with the three-electrode system (as shown in FIG. 6, the initial photocurrent density was 0.85 mA/cm.sup.2). The photocurrent of the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor has remained unchanged all the time, whereas the photocurrent of the CuO photoelectric sensor attenuated rapidly with time, which indicated that the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor was more stable than the CuO photoelectric sensor during a photoelectrochemical test.

[0056] 2. Test of concentration of arginine through 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor

[0057] After the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor was incubated in an arginine solution, 8-hydroxyquinoline and arginine were specifically combined, so that arginine was immobilized on a surface of a photoelectrode. As the amounts of arginine immobilized on the surface of the photoelectrode were different when the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor was incubated in arginine of different concentrations, different photocurrents were displayed (as shown in FIG. 7). The concentration of arginine may be determined according to the magnitude of the photocurrent, thereby achieving the purpose of detection.

[0058] Under optimized experimental conditions, after being immersed in borate buffered saline (BBS, pH=9) containing arginine of different concentrations, the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor was subjected to a photochemical test. As shown in FIG. 7 and FIG. 8, the photocurrent density increased steadily in the process during which the concentration of arginine increased from 1.0*10.sup.−5 mol/L to 1.0*10.sup.−3 mol/L. After fitting, a functional relationship between the concentration of arginine and the photocurrent density was as follows:

ΔI=a+b×log.sub.10C.sub.L-ARg,

[0059] where a=23.85703±0.27555, b=4.36164±0.0637, R.sup.2=99.893%, which indicated that the fitting degree was good.

[0060] 3. Anti-interference test of 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor

[0061] In the three-electrode system of borate buffered saline (BBS, pH=9), the detection of common amino acids by the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor was investigated. In the detection of L-arginine (L-Arg), L-valine (L-Val), L-glutamine (L-Glu), L-alanine (L-Ala), L-glycine (L-Gly), L-proline (L-Pro), and ascorbic acid (AA), all of which the concentrations were 100 μmol/L, and a mixed sample (including all the amino acids mentioned above), as shown in FIG. 9, the sensor had an obvious response to L-arginine, but no obvious response to the other amino acids. In addition, a value of response of the sensor to the mixed sample was also close to a value of response to L-arginine, which indicated that the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor had a good anti-interference capability in the detection of arginine.

Embodiment 2

[0062] A CuV.sub.2O.sub.6 -based photoelectric sensor is prepared through the following steps.

[0063] (1) Pre-sputtering is started for 300 s through a direct-current reactive magnetron co-sputtering method after a target metal Cu and a target metal V are installed on a magnetron sputtering instrument, wherein a substrate is FTO glass, a sputtering mode is co-sputtering of Cu and V, a chamber atmosphere of the magnetron sputtering instrument is a mixture of argon and oxygen, and the following parameters are set: the power of the target Cu is 10 W, the power of the target V is 100 W, the sputtering pressure is 0.5 Pa, the temperature of the substrate is 200° C., and the rotating speed of a substrate holder is 5 r/min. After glow stabilizes, a substrate baffle is opened to start deposition for 6,000 s. A sample is taken out after the deposition is ended and calcined at 200° C. for 2 h in an air atmosphere to acquire a CuV.sub.2O.sub.6 thin film.

[0064] (2) A 100 mmol/L 8-hydroxyquinoline-ethanol solution is mixed with Nafion with the mass fraction of 5% according to the volume ratio of 9:1 to acquire an 8-hydroxyquinoline solution. 40 μL of the prepared 8-hydroxyquinoline solution is loaded on the CuV.sub.2O.sub.6 thin film acquired in step (1) through a spin-coating method to acquire the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor, wherein a spin coater rotates at the rotating speed of 500 r/min for 40 s.

Embodiment 3

[0065] A CuV.sub.2O.sub.6 -based photoelectric sensor is prepared through the following steps.

[0066] (1) Pre-sputtering is started for 1,200 s through a direct-current reactive magnetron co-sputtering method after a target metal Cu and a target metal V are installed on a magnetron sputtering instrument, wherein a substrate is FTO glass, a sputtering mode is co-sputtering of Cu and V, a chamber atmosphere of the magnetron sputtering instrument is a mixture of argon and oxygen, and the following parameters are set: the power of the target Cu is 50 W, the power of the target V is 500 W, the sputtering pressure is 2.5 Pa, the temperature of the substrate is 400° C., and the rotating speed of a substrate holder is 30 r/min. After glow stabilizes, a substrate baffle is opened to start deposition for 1,000 s. A sample is taken out after the deposition is ended and calcined at 550° C. for 0.5 h in an air atmosphere to acquire a CuV.sub.2O.sub.6 thin film.

[0067] (2) A 1,400 mmol/L 8-hydroxyquinoline-ethanol solution is mixed with Nafion with the mass fraction of 5% according to the volume ratio of 9:1 to acquire an 8-hydroxyquinoline solution. 10 μL of the prepared 8-hydroxyquinoline solution is loaded on the CuV.sub.2O.sub.6 thin film acquired in step (1) through a spin-coating method to acquire the 8-hydroxyquinoline-modified CuV.sub.2O.sub.6 photoelectric sensor, wherein a spin coater rotates at the rotating speed of 2,000 r/min for 9 s.

[0068] The photoelectric sensors prepared in Embodiments 1-3 were immersed in borate buffered saline (BBS, pH=9) containing arginine of different concentrations, i.e., 10 μmol/L, 20 μmol/L, 40 μmol/L, 100 μmol/L, 200 μmol/L, 400 μmol/L, 1,000 μmol/L, respectively for incubation for 120 min, and then taken out. Electrode photocurrents of the sensors were tested with a three-electrode system, fitting working curves of the photocurrent densities and the concentrations of arginine were drawn, and then arginine in the samples to be tested were detected with a standard addition method.

[0069] The electrode photocurrent of the sensor was tested with the three-electrode system under the voltage of 1.2 V vs RHE.

[0070] The above description of the embodiments is only used to help understanding the technical solutions and core concept of the present invention. It should be noted that those skilled in the art can make some improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications shall fall within the protection scope of the present invention.