CN-121975258-A - Double-emission carbon dot hydrogel film and preparation method and application thereof

CN121975258ACN 121975258 ACN121975258 ACN 121975258ACN-121975258-A

Abstract

The invention discloses a double-emission carbon dot hydrogel film, a preparation method and application thereof, and relates to the technical field of analysis detection and functional materials. The double-emission carbon dot hydrogel film takes polyvinyl alcohol hydrogel as a carrier, wherein double-emission carbon dots (O-CDs) synthesized by taking L-glutamic acid and O-phenylenediamine as precursors are uniformly dispersed. O-CDs have dual emission peaks at 375 nm for 400 nm and 530 for nm. The dual-emission carbon dot hydrogel film is applied to Cu 2+ and Ag + portable visual detection, wherein the portable visual detection is RGB-based dual-mode measurement, and comprises fluorescence colorimetric determination in solution and a visual detection film assisted by a smart phone. The dual-mode strategy can realize the rapid, reliable and synchronous detection of Cu 2+ and Ag + within 10min without a precise instrument, breaks through the limitation of the traditional single-mode detection, and provides a robust platform for on-site metal ion monitoring.

Inventors

HAN YONG
WANG HUI
LUO XIAOYU
LI CHENGQIAN

Assignees

陇东学院

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (9)

1. The preparation method of the double-emission carbon dot hydrogel film is characterized by comprising the following steps of: s1, preparing double-emission carbon dots, namely dissolving L-glutamic acid and o-phenylenediamine in absolute ethyl alcohol, performing ultrasonic treatment to form a homogeneous solution, transferring the homogeneous solution into a polytetrafluoroethylene liner autoclave for reaction, naturally cooling to room temperature after the reaction is finished, and centrifuging and filtering to obtain a double-emission carbon dot solution; S2, preparing a polyvinyl alcohol solution, namely dissolving polyvinyl alcohol in ultrapure water, heating and stirring until the polyvinyl alcohol solution is completely dissolved to obtain the polyvinyl alcohol solution; and S3, forming a hydrogel film, namely adding a double-emission carbon dot solution after removing bubbles from a polyvinyl alcohol solution to obtain a mixture, fully mixing and degassing the mixture through magnetic stirring, injecting the mixture into a 12-hole culture plate, and carrying out three-cycle continuous freeze thawing cycles to obtain the double-emission carbon dot hydrogel film.
2. The preparation method according to claim 1, wherein in the step S1, the molar ratio of the L-glutamic acid to the o-phenylenediamine is 1:2, the reaction temperature is 210 ℃, the time is 10 h, the centrifugal rotating speed is 8000 r/min, and the time is 20 min.
3. The process according to claim 1, wherein in step S2, the solid-to-liquid ratio of the polyvinyl alcohol to the ultrapure water is 1:10 in terms of g: mL, the heating temperature is 95℃and the stirring time is 4 h.
4. The method according to claim 1, wherein in the step S3, the polyvinyl alcohol solution is used for removing bubbles, namely, the polyvinyl alcohol solution is kept at 20min at 37 ℃, the volume ratio of the polyvinyl alcohol solution after removing the bubbles to the double-emission carbon point solution is 7:3, and the freeze thawing cycle is that the polyvinyl alcohol solution is changed to 25 ℃ to be kept at 4h after being kept at 20-20 ℃ for h.
5. The double-emission carbon dot hydrogel film prepared by the preparation method according to any one of claims 1-4, wherein the film uses polyvinyl alcohol hydrogel as a carrier, double-emission carbon dots are uniformly dispersed in the polyvinyl alcohol hydrogel, and the double-emission carbon dots have two fluorescence emission peaks at 400 nm and 530 nm under excitation of 375 nm wavelength.
6. The method for preparing the double-emission carbon dot hydrogel film according to any one of claims 1 to 4, wherein the double-emission carbon dot and/or double-emission carbon dot hydrogel film is applied to Cu 2+ and Ag + portable visual detection.
7. The use of claim 6, wherein the portable visual detection is a dual-mode RGB-based measurement comprising a fluorescence colorimetric assay in solution and a smartphone-assisted visual detection membrane.
8. The application of the method of claim 7, wherein the smart phone-assisted visual detection film comprises a shading camera bellows, 365 nm ultraviolet lamps and a smart phone, and when in detection, a cuvette containing a sample to be detected and a double-emission carbon point hydrogel film is placed in the camera bellows, the ultraviolet lamps are started, an image is shot in real time through the smart phone, RGB values are extracted through an application program, and the concentration of target ions Cu 2+ and Ag + is quantified based on the RGB values and a preset calibration curve.
9. The application of the portable device is characterized in that Wi-Fi communication is integrated in fluorescent colorimetric determination in the solution, a core component comprises a double-sample chamber, an LED excitation light source, a color sensor, an electronic module and a cuvette, a smart phone is used as a remote terminal to realize data display and interaction, the electronic module takes a microcontroller as a core and is provided with a resistor and an LCD module, the double-emission carbon point solution and BR buffer solution are incubated for 2min at room temperature to obtain the double-emission carbon point sensor solution before detection, the cuvette containing the double-emission carbon point sensor solution and the liquid to be detected is placed in the double-sample chamber during detection, the sample is excited by the LED light source to generate fluorescent response, signals are captured by the color sensor and converted into RGB values, and the RGB values are transmitted to the smart phone to quantitatively analyze the concentrations of Cu 2+ and Ag + based on a preset calibration curve.

Description

Double-emission carbon dot hydrogel film and preparation method and application thereof Technical Field The invention relates to the technical field of analysis detection and functional materials, in particular to a double-emission carbon dot hydrogel film and a preparation method and application thereof. Background At present, the detection of heavy metal ions Cu 2+ and Ag + in water or food mainly depends on the following technologies: Large-scale precision instruments such as Atomic Absorption Spectroscopy (AAS), inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma emission spectroscopy (ICP-OES), and the like. The method has low detection limit and high accuracy, and is a laboratory standard method. However, the method depends on large-scale instruments, is difficult to detect rapidly on site, has large size and high price of AAS, ICP-MS and other instruments, requires professional operators and laboratory conditions, and is not suitable for basic units, sites or emergency scenes. The traditional colorimetry and photometry are to utilize a color reaction between a color reagent and Cu 2+ and Ag +, and to measure absorbance and quantify through a spectrophotometer. However, most of the methods are single metal ion detection, so that it is difficult to distinguish Cu 2+ from Ag + at the same time, most of the existing fluorescent or colorimetric probes are designed for a certain metal ion or similar signals are generated by different metal ions, so that Cu 2+ and Ag + cannot be quantified and distinguished at the same time, and the adaptability to complex samples is poor. The fluorescent probe detection method is to utilize fluorescent materials such as an organic micromolecular probe, a metal complex, quantum dots, carbon dots and the like to generate fluorescence enhancement/quenching or spectrum displacement to target ions so as to realize fluorescent detection. However, the single-channel signal of the method has poor anti-interference capability and insufficient quantitative accuracy, and a plurality of fluorescent probes only depend on single-wavelength emission intensity change and are easily influenced by light source intensity, probe concentration, shooting conditions and the like, so that the reproducibility and the quantitative accuracy are insufficient, and the real and reliable on-site monitoring is difficult to realize. The liquid phase probe is unfavorable for carrying and long-term storage, and the problems of leakage, volatilization and microbial pollution exist in the liquid phase detection form of the traditional probe solution and cuvette, so that the liquid phase probe is inconvenient for transportation and long-term storage, and is also unfavorable for one-time and standardized on-site detection. The intelligent mobile phone auxiliary detection technology is that a fluorescent probe or a test strip is combined with an intelligent mobile phone camera to realize on-site quantitative or semi-quantitative detection through RGB values and the like, but the intelligent mobile phone auxiliary detection technology is concentrated on a single ion or a single emission channel. Meanwhile, the detection mode of the smart phone is not perfect, part of the existing smart phone auxiliary methods only stay in the subjective judgment stage of photographing and color viewing, lack of a stable solid/hydrogel carrier and systematic RGB quantitative analysis flow, large measurement result deviation and insufficient repeatability. Therefore, a portable detection material and a method which can detect Cu 2+ and Ag + simultaneously, rapidly and visually, are convenient to carry, good in stability and strong in anti-interference capability are developed, and have important practical application values. Disclosure of Invention Aiming at the problems, the invention provides a double-emission carbon point hydrogel film, a preparation method and application thereof, and the rapid, simultaneous and visual field detection of Cu 2+ and Ag + is realized through the double-emission carbon point, the hydrogel film, the intelligent mobile phone RGB analysis and the portable light source structure integration. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The invention aims at providing a preparation method of a double-emission carbon point hydrogel film, which comprises the following steps: S1, preparing double-emission carbon dots, namely dissolving L-glutamic acid and O-phenylenediamine in absolute ethyl alcohol, performing ultrasonic treatment to form a homogeneous solution, transferring the homogeneous solution into a polytetrafluoroethylene liner autoclave for reaction, naturally cooling to room temperature after the reaction is finished, and performing centrifugation and filtration to obtain orange-red double-emission carbon dot solution (O-CDs solution); s2, preparing a polyvinyl alcohol solution, namely dissolving polyvinyl alcoh