A strong anti-interference, high sensitivity colorimetric-fluorescence-upconversion luminescence three-mode reagent detects hydrogen peroxide

Abstract

The application provides a strong anti-interference, high sensitivity colorimetric-fluorescence-upconversion luminescence three-mode reagent for detecting hydrogen peroxide, which is composed of N-n-hexanoic acid-4-boronic acid pinacol ester-1,8-naphthalimide organic small molecule fluorescent probe, NaYF4, Yb, Tm oleic acid wrapped rare earth doped upconversion nanomaterial, tetrabutylammonium hydroxide catalyst and mixed solvent of ethanol and ultrapure water. The three-mode reagent has the functions of colorimetric, fluorescent and upconversion luminescence detection for hydrogen peroxide. The three-mode reagent itself is a light yellow solution, which turns into golden color within 5s after contacting with hydrogen peroxide. Under the excitation of 468nm blue light, the fluorescence changes from green to yellow green, and the upconversion luminescence changes from blue to red. The three-mode reagent has semi-quantitative ability for hydrogen peroxide, and can realize self-calibration function through the combination of colorimetric channel, fluorescent channel and upconversion luminescence channel. The rapid trace detection of hydrogen peroxide is realized, and the influence of background interference on the detection of hydrogen peroxide in complex environment is compensated. The development of the three-mode reagent can provide effective technical support for the field of trace detection of non-standard explosives in actual environment.

Description

Technical Field

[0001] This invention belongs to the field of analytical detection and provides a three-mode reagent for detecting hydrogen peroxide with strong anti-interference and high sensitivity of colorimetry-fluorescence-upconversion luminescence. Background Technology

[0002] Hydrogen peroxide is a major raw material for the preparation of peroxide explosives, and it is also a decomposition product of peroxide explosives. Therefore, the on-site ultrasensitive, rapid, specific and accurate identification and detection of hydrogen peroxide is of great practical significance.

[0003] Currently, given the special significance of hydrogen peroxide detection, scholars both domestically and internationally have conducted extensive research. Fluorescent detection technology has attracted widespread attention due to its high sensitivity, fast reaction speed, strong specificity, visualized detection signal, and ease of operation. To date, researchers have explored numerous small organic molecule fluorescent probes for hydrogen peroxide detection. For example, Chinese patent CN 109060739 reports a fluorescent sensing material that loads a boron-nitrogen aromatic ring compound onto a thin film. The sensing film itself has weak fluorescence, but emits strong fluorescence upon contact with hydrogen peroxide, thus enabling the detection of hydrogen peroxide. Chinese patent CN 108623611 reports a rhodamine derivative fluorescent probe that can specifically recognize hydrogen peroxide. The fluorescent probe itself is almost non-fluorescent, but rapidly emits strong fluorescence after interacting with hydrogen peroxide. Furthermore, the research group of Professor Han Keli at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, designed and synthesized a dopamine-anthocyanin fluorescent probe to achieve fluorescence quenching detection of hydrogen peroxide (Chemical Communications 2012, 48, 4980-4982). However, as a single-channel detection technique, fluorescence detection is inevitably subject to fluorescence interference from background fluorescence and common complex substances in daily life (such as dust, fluorescent dyes, or plants) in practical applications, leading to unreliable detection results. Therefore, the directional design of highly interference-resistant detection based on organic small molecule fluorescent probes is of great significance for achieving ultra-precise visual detection.

[0004] A common and efficient strategy to address this issue is to construct a dual-mode visualization detection platform that generates two independent detection signals, thereby effectively reducing the influence and potential interference from the external environment. Currently, researchers have developed many organic small molecule fluorescent probes that integrate colorimetric and fluorescence dual-mode detection. For example, Professor Li Haitao's research group at Hunan Normal University designed and synthesized an organic small molecule fluorescent probe, (E)-2-(2-(4-((4-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)benzyl)oxy)styryl)-4H-methylene-4-yl)malonium, achieving colorimetric and dual-mode fluorescence detection of hydrogen peroxide, with the solution color changing from yellow to purple and the fluorescence changing from colorless to red (Sensors and Actuators B: Chemical 2019, 280, 120-128). Professor Wu Junchen's research group at East China University of Science and Technology designed a probe based on regulating the fluorescence resonance energy transfer between 1,8-naphthalimide boronic acid and anthocyanin fluorescent dyes, achieving colorimetric and dual-mode fluorescence detection of hydrogen peroxide, with the color changing from colorless to blue and the fluorescence changing from blue to red (Dyes and Pigments 2018, 155, 143-149). However, most reported dual-mode detection platforms using small organic molecule fluorescent probes emit low-energy fluorescence while being excited by high-energy light. In complex application scenarios, this is easily interfered with by colored and fluorescent substances, leading to inaccurate and unreliable detection. In contrast, rare-earth-doped upconversion nanomaterials can convert low-energy near-infrared light into high-energy ultraviolet or visible light. Due to their unique upconversion luminescence mechanism, they possess significant advantages such as high photochemical stability, low autofluorescence signal, excellent signal-to-noise ratio, and wide luminescence range. They can effectively avoid background interference in complex environments. For example, the research group of Professor Gu Yueqing at China Pharmaceutical University designed and synthesized an upconversion nanoprobe using upconversion nanomaterials as the energy donor and dicyanomethyl 4H-pyran as the energy acceptor. When hydrogen peroxide is present, the upconversion luminescence changes from green to red (ACS Appl Mater Interfaces 2019, 11, 7441-7449). Although this upconversion nanoprobe achieves interference from colored and fluorescent substances in complex environments, the detection limit for hydrogen peroxide in this system is relatively high at 0.168 μM. Therefore, exploring a simple and efficient strategy to achieve high sensitivity and strong anti-interference multimodal detection of hydrogen peroxide by utilizing highly sensitive organic small molecule fluorescent probes and rare earth-doped upconversion nanomaterials with strong anti-interference capabilities is a significant and valuable challenge. Summary of the Invention

[0005] The purpose of this invention is to provide a highly sensitive, interference-resistant, colorimetric-fluorescence-upconversion luminescence trimodal reagent for detecting hydrogen peroxide. This reagent consists of an organic small-molecule fluorescent probe (N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide), rare-earth-doped upconversion nanomaterials encapsulated in NaYF4,Yb,Tm oleic acid, a tetrabutylammonium hydroxide catalyst, and a mixed solvent of ethanol and ultrapure water. The trimodal reagent of this invention provides colorimetric, fluorescence, and upconversion luminescence detection of hydrogen peroxide. The reagent itself is a light yellow solution that turns golden within 5 seconds of contact with hydrogen peroxide. Under 468nm blue light excitation, the fluorescence changes from green to yellow-green, and under 980nm near-infrared light excitation, the upconversion luminescence changes from blue to red. This trimodal reagent exhibits superior interference resistance and excellent detection limits. The detection process does not require complex analytical equipment, enabling rapid trace detection of hydrogen peroxide. Simultaneously, it compensates for background interference in hydrogen peroxide detection in complex environments. Therefore, the development of this three-mode reagent can provide effective technical support for the detection of trace amounts of non-standard explosives in real-world environments.

[0006] The invention discloses a three-mode reagent for detecting hydrogen peroxide with strong anti-interference and high sensitivity of colorimetry-fluorescence-upconversion luminescence. The specific operation is as follows:

[0007] Preparation of the three-mode reagent:

[0008] a. This reagent consists of 1 mM of N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide organic small molecule fluorescent probe, 0.5 mg / mL of rare earth-doped upconversion nanomaterials coated with NaYF4,Yb,Tm oleic acid, 1 mM of tetrabutylammonium hydroxide catalyst, and a mixed solvent of ethanol and ultrapure water in a volume ratio of 18:1. 2 mM of N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide organic small molecule fluorescent probe is added to 1 mL of ethanol and mixed thoroughly. Then, 1.25 mg / mL of rare earth-doped upconversion nanomaterials coated with NaYF4,Yb,Tm oleic acid is added to 0.8 mL of ethanol and mixed thoroughly. Next, 20 mM of tetrabutylammonium hydroxide catalyst is added to 0.1 mL of ultrapure water and mixed thoroughly. Finally, the ethanol mixture and the ultrapure water mixture are mixed thoroughly to obtain the three-mode reagent.

[0009] Detection of hydrogen peroxide using a three-mode reagent:

[0010] b. Place the trimodal reagent obtained in step a into a quartz cuvette. After adding hydrogen peroxide, the solution color rapidly changes from light yellow to gold within 5 seconds. Under 468 nm blue light excitation, the fluorescence changes from green to yellow-green. Under 980 nm near-infrared light excitation, the upconversion emission changes from blue to red. When the hydrogen peroxide concentration is 0 μM-125 μM, the absorption peak intensity at 454 nm is linearly related to the hydrogen peroxide concentration, with a detection limit of 375.00 nM. When the hydrogen peroxide concentration is 0 μM-70 μM, the fluorescence emission peak intensity at 558 nm is linearly related to the hydrogen peroxide concentration, with a detection limit of 4.34 nM. When the hydrogen peroxide concentration is 0 μM-200 μM, the ratio of the upconversion emission peak intensity at 478 nm to the upconversion emission peak intensity at 646 nm is linearly related to the hydrogen peroxide concentration, with a detection limit of 94.36 nM.

[0011] The three-mode reagent has strong anti-interference ability in detecting hydrogen peroxide. In an environment where gold pigment is present, hydrogen peroxide can be detected through the fluorescence channel and the upconversion luminescence channel; in an environment where yellow-green fluorescent dye is present, hydrogen peroxide can be detected through the colorimetric channel and the upconversion luminescence channel; and in an environment where both gold pigment and yellow-green fluorescent dye are present, hydrogen peroxide can be detected through the upconversion luminescence channel.

[0012] This invention discloses a three-mode reagent for detecting hydrogen peroxide using a highly interference-resistant and sensitive colorimetric-fluorescence-upconversion luminescence method. The detection principle is as follows: the organic small molecule fluorescent probe N-hexanoic acid-4-boronic acid pinacol ester-1,8-naphthalimide has a recognition site of borate pinacol ester, which can hydrolyze with hydrogen peroxide to phenol under the action of tetrabutylammonium hydroxide catalyst. This results in intramolecular charge transfer of the fluorophore 1,8-naphthalimide. The unique design of the carboxylic acid group on the organic small molecule fluorescent probe of this invention can consume the hydroxyl groups generated during the reaction with hydrogen peroxide, effectively promoting the reaction process and thus greatly improving the response rate and sensitivity of the organic small molecule fluorescent probe for hydrogen peroxide detection. The solution color rapidly changes from light yellow to gold, and under 468nm blue light excitation, the fluorescence changes from green to yellow-green. In addition, the emission spectrum of the rare-earth-doped upconversion nanomaterials largely overlaps with the UV-Vis absorption spectrum of the hydrogen peroxide-induced product molecules, creating an internal filtering effect. This causes the upconversion luminescence to change from blue to red under 980nm near-infrared light excitation, ultimately achieving colorimetric-fluorescence-upconversion luminescence trimodal detection of hydrogen peroxide. This trimodal reagent features accurate identification, high specificity, high sensitivity, fast reaction speed, simple operation, and ease of widespread application.

[0013] The present invention discloses a three-mode reagent for detecting hydrogen peroxide with strong anti-interference and high sensitivity of colorimetry-fluorescence-upconversion luminescence. The specific method is as follows:

[0014] Hydrogen peroxide was diluted in ultrapure water to prepare aqueous solutions of 0 mM, 0.2 mM, 0.4 mM, 0.6 mM, 0.8 mM, 1.0 mM, 1.4 mM, 1.6 mM, 1.8 mM, 2.0 mM, 2.5 mM, 3.0 mM, 4.0 mM, 5.0 mM, and 6.0 mM.

[0015] Measure 1.9 mL of the same three-mode reagent into a reagent bottle using a pipette, add 100 μL of hydrogen peroxide aqueous solution of different concentrations, and then use a digital camera to record the colorimetric detection image, fluorescence detection image and upconversion luminescence image before and after the reaction.

[0016] Alternatively, 1.9 mL of the three-mode reagent can be pipetted into a quartz cuvette, and then 100 μL of hydrogen peroxide aqueous solution of different concentrations can be added. The UV-Vis absorption spectrum can be scanned using a UV-Vis spectrophotometer to measure the UV-Vis absorption spectrum of the three-mode reagent after detecting different concentrations of hydrogen peroxide. Then, with the maximum absorbance as the ordinate and the hydrogen peroxide concentration as the abscissa, a linear equation in one variable can be fitted to determine the colorimetric detection limit of the three-mode reagent.

[0017] Alternatively, 1.9 mL of the three-mode reagent can be pipetted into a quartz cuvette, and then 100 μL of hydrogen peroxide aqueous solution of different concentrations can be added. The fluorescence emission spectrum of the three-mode reagent after detecting different concentrations of hydrogen peroxide can be scanned using a fluorescence spectrometer. The fluorescence emission spectrum of the three-mode reagent after detecting different concentrations of hydrogen peroxide can be measured. Then, a linear equation in one variable can be fitted with the maximum fluorescence emission peak intensity as the ordinate and the hydrogen peroxide concentration as the abscissa to determine the fluorescence detection limit of the three-mode detection system.

[0018] Alternatively, 1.9 mL of the three-mode reagent can be pipetted into a quartz cuvette, and then 100 μL of hydrogen peroxide aqueous solution of different concentrations can be added. Upconversion emission spectra can be scanned using a fluorescence spectrometer to determine the upconversion emission spectra of the three-mode reagent after detecting different concentrations of hydrogen peroxide. Then, a linear equation in one variable can be fitted with the maximum upconversion emission peak intensity as the ordinate and the hydrogen peroxide concentration as the abscissa to determine the upconversion luminescence detection limit of the three-mode reagent.

[0019] The present invention describes a three-mode reagent for detecting hydrogen peroxide with strong anti-interference and high sensitivity of colorimetry-fluorescence-upconversion luminescence. It is mainly used to detect hydrogen peroxide, a precursor of explosives, and solves the current problem of not being able to detect hydrogen peroxide accurately, quickly, visually, and with high sensitivity in complex environments.

[0020] This invention describes a highly sensitive, interference-resistant, colorimetric-fluorescence-upconversion luminescence three-mode reagent for detecting hydrogen peroxide. The reagent itself is a light yellow solution that turns golden within 5 seconds of contact with hydrogen peroxide. Under 468nm blue light excitation, the fluorescence changes from green to yellow-green. Under 980nm near-infrared light excitation, the upconversion luminescence changes from blue to red. This three-mode reagent exhibits superior interference resistance, unaffected by common oxidants (sodium persulfate, sodium bromate, sodium nitrite, etc.), easily explosive materials (sodium perchlorate, potassium chlorate, urea, etc.), water-soluble metal salts (sodium acetate, sodium chloride, potassium bromide, etc.), daily necessities (dishwashing liquid, hand sanitizer, perfume, etc.), and complex environments (containing gold pigments and yellow-green fluorescent dyes). Furthermore, this three-mode reagent has extremely low detection limits (UV-Vis detection limit of 375.00 nM, fluorescence detection limit of 4.34 nM, and upconversion luminescence detection limit of 94.36 nM). This tri-mode reagent compensates for background interference when detecting hydrogen peroxide in complex environments, providing an effective technical means for the field of optical detection.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. The three-mode reagent described in this invention can achieve strong anti-interference detection of hydrogen peroxide in complex environments;

[0023] 2. The three-mode reagent described in this invention has a semi-quantitative ability for hydrogen peroxide, and at the same time, it achieves self-calibration function by combining the colorimetric channel, fluorescence channel and upconversion luminescence channel, thereby realizing accurate detection of hydrogen peroxide;

[0024] 3. The unique design of the carboxylic acid group on the organic small molecule fluorescent probe in the three-mode reagent of the present invention makes the detection of hydrogen peroxide highly sensitive, with a detection limit as low as 4.34 nM and a fast detection speed, which can realize detection in colorimetric, fluorescence and upconversion luminescence channels within 5 seconds;

[0025] 4. The three-mode reagent described in this invention can detect hydrogen peroxide without the need for complex analytical equipment and can be directly detected by naked eye;

[0026] 5. The three-mode reagent described in this invention does not require any pretreatment of the analyte, is simple to operate, and is easy to promote and apply. It can fully realize the purpose of low-cost colorimetric, fluorescence, and upconversion luminescence three-mode reagent detection of hydrogen peroxide. Attached Figure Description

[0027] Figure 1The concentrations of N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide and NaYF4,Yb,Tm in a mixed solvent of ethanol and ultrapure water are 1 mM and 0.5 mg / mL, respectively, and the concentration of tetrabutylammonium hydroxide is 1 mM. The UV-Vis absorption spectra before and after reaction with a 300 μM hydrogen peroxide aqueous solution are shown below. Figure 1 Left), fluorescence emission spectrum ( Figure 1 (middle) and upconversion emission spectrum ( Figure 1 (Right), where the inset shows photographs taken by a camera of the changes in color, fluorescence, and upconversion luminescence of the detection system before and after the reaction;

[0028] Figure 2 The UV-Vis absorption spectra obtained by reacting N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide and NaYF4,Yb,Tm in a mixed solvent of ethanol and ultrapure water at concentrations of 1 mM and 0.5 mg / mL, respectively, with tetrabutylammonium hydroxide at a concentration of 1 mM, with hydrogen peroxide at a concentration of 0 μM-300 μM, are shown in the figure. Figure 2 The right side shows a linear equation obtained by fitting hydrogen peroxide concentration as the x-axis and the absorbance at 454 nm as the y-axis.

[0029] Figure 3 The fluorescence emission spectrum of this invention, obtained after reacting N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide and NaYF4,Yb,Tm in a mixed solvent of ethanol and ultrapure water at concentrations of 1 mM and 0.5 mg / mL respectively, and tetrabutylammonium hydroxide at a concentration of 1 mM with hydrogen peroxide at a concentration of 0 μM-300 μM, is shown in the figure. Figure 3 The right side shows a linear equation obtained by fitting hydrogen peroxide concentration as the x-axis and fluorescence emission peak intensity at 558 nm as the y-axis.

[0030] Figure 4 The upconversion emission spectrum obtained by reacting N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide and NaYF4,Yb,Tm in a mixed solvent of ethanol and ultrapure water at concentrations of 1 mM and 0.5 mg / mL, respectively, with tetrabutylammonium hydroxide at a concentration of 1 mM, with hydrogen peroxide at a concentration of 0 μM-300 μM is shown in the figure. Figure 4 The right side shows a linear equation obtained by fitting hydrogen peroxide concentration as the x-axis and the ratio of the upconversion emission peak intensity at 478 nm to the upconversion emission peak intensity at 646 nm as the y-axis.

[0031] Figure 5The colorimetric results obtained by digital camera after reacting N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide and NaYF4,Yb,Tm in a mixed solvent of ethanol and ultrapure water at concentrations of 1 mM and 0.5 mg / mL, respectively, with tetrabutylammonium hydroxide at a concentration of 1 mM, with hydrogen peroxide at a concentration of 0 μM-300 μM were obtained. Figure 5 (above), fluorescence ( Figure 5 (middle) and upconversion luminescence image ( Figure 5 Down);

[0032] Figure 6 Colorimetric photographs of the reactions of N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide and NaYF4,Yb,Tm in a mixed solvent of ethanol and ultrapure water at concentrations of 1 mM and 0.5 mg / mL, respectively, and tetrabutylammonium hydroxide at a concentration of 1 mM, with 300 μM of hydrogen peroxide, sodium persulfate, sodium bromate, sodium nitrite, potassium nitrate, sodium perchlorate, potassium chlorate, urea, sucrose, trinitrotoluene, 2,4-dinitrotoluene, sodium acetate, sodium chloride, sodium hydroxide, magnesium chloride, sodium fluoride, potassium bromide, magnesium sulfate, sodium dodecyl sulfate, dishwashing liquid, hand sanitizer, and perfume. Figure 6 Above), Fluorescent photographs ( Figure 6 (middle) and upconversion luminescence photographs ( Figure 6 Down).

[0033] Figure 7 The concentrations of N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide and NaYF4,Yb,Tm in a mixed solvent of ethanol and ultrapure water were 1 mM and 0.5 mg / mL, respectively, and the concentration of tetrabutylammonium hydroxide was 1 mM. Colorimetric measurements were taken with a digital camera before and after the reaction with 98 ppm hydrogen peroxide vapor on a complex sponge containing gold pigment, yellow-green fluorescent dye, or both. Figure 7 (above), fluorescence ( Figure 7 (middle) and upconversion luminescence image ( Figure 7 Down). Detailed Implementation

[0034] The present invention will be further described below through specific embodiments, but the invention is not limited to these embodiments.

[0035] Example 1

[0036] The invention discloses a three-mode reagent for detecting hydrogen peroxide with strong anti-interference and high sensitivity of colorimetry-fluorescence-upconversion luminescence. The specific operation is as follows:

[0037] Preparation of the three-mode reagent:

[0038] This reagent consists of 1 mM of N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide organic small molecule fluorescent probe, 0.5 mg / mL of rare earth-doped upconversion nanomaterials coated with NaYF4,Yb,Tm oleic acid, 1 mM of tetrabutylammonium hydroxide catalyst, and a mixed solvent of ethanol and ultrapure water in a volume ratio of 18:1. 2 mM of the N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide organic small molecule fluorescent probe is added to 1 mL of ethanol and mixed thoroughly. Then, 1.25 mg / mL of rare earth-doped upconversion nanomaterials coated with NaYF4,Yb,Tm oleic acid is added to 0.8 mL of ethanol and mixed thoroughly. Next, 20 mM of the tetrabutylammonium hydroxide catalyst is added to 0.1 mL of ultrapure water and mixed thoroughly. Finally, the ethanol mixture and the ultrapure water mixture are mixed thoroughly to obtain the three-mode reagent.

[0039] Detection of hydrogen peroxide using a three-mode reagent:

[0040] Measure 1.9 mL of the three-mode reagent into a quartz cuvette, then add 100 μL of a 6 mM hydrogen peroxide standard aqueous solution prepared in ultrapure water. Within 5 seconds, the solution color rapidly changes from light yellow to gold. Under 468 nm blue light excitation, the fluorescence changes from green to yellow-green. Under 980 nm near-infrared light excitation, the upconversion luminescence changes from blue to red.

[0041] Example 2

[0042] The preparation of the trimodal reagent was carried out according to the examples;

[0043] Measure 1.9 mL of the three-mode reagent into a quartz cuvette, and then add 100 μL of 0-2.5 mM hydrogen peroxide standard aqueous solution prepared by diluting hydrogen peroxide in ultrapure water. Perform UV-Vis absorption spectroscopy scanning using a UV-Vis spectrophotometer. By comparing the UV-Vis absorption spectra, it can be seen that the absorption peak intensity at 454 nm has a linear relationship with the hydrogen peroxide concentration, and the detection limit is 375.00 nM.

[0044] Example 3

[0045] The preparation of the trimodal reagent was carried out according to the examples;

[0046] Measure 1.9 mL of the three-mode reagent into a quartz cuvette, and then add 100 μL of 0-1.4 mM hydrogen peroxide standard aqueous solution prepared by diluting hydrogen peroxide in ultrapure water. Perform fluorescence emission spectrum scanning using a fluorescence spectrometer. By comparing the fluorescence spectrum, it can be seen that the intensity of the fluorescence emission peak at 558 nm is linearly related to the concentration of hydrogen peroxide, and the detection limit is 4.34 nM.

[0047] Example 4

[0048] The preparation of the trimodal reagent was carried out according to the examples;

[0049] 1.9 mL of the three-mode reagent was placed in a quartz cuvette, and 100 μL of 0-4 mM hydrogen peroxide standard aqueous solution prepared by diluting hydrogen peroxide in ultrapure water was added. Upconversion emission spectrum was scanned using a fluorescence spectrometer. By comparing the upconversion emission spectrum, it can be seen that the ratio of the upconversion emission peak intensity at 478 nm to that at 646 nm is linearly related to the hydrogen peroxide concentration, and the detection limit is 94.36 nM.

[0050] Example 5

[0051] 36 μL of the three-mode reagent was dropped onto blank sponges, sponges with gold pigment, sponges with yellow-green dye, and multi-sponge substrates containing both gold and yellow-green dye. Each substrate was then placed in 98 ppm hydrogen peroxide vapor for 180 seconds. The samples were then photographed directly with a digital camera under fluorescent light, 468 nm blue light excitation, and 980 nm near-infrared light excitation. The reagent detected hydrogen peroxide in the presence of gold pigment through both fluorescence and upconversion luminescence channels; in the presence of yellow-green fluorescent dye, it detected hydrogen peroxide through both colorimetric and upconversion luminescence channels; and in the presence of both gold pigment and yellow-green fluorescent dye, it detected hydrogen peroxide through the upconversion luminescence channel.

[0052] Although the above embodiments describe the present invention, it should be understood that the proportions of reagent components in the present invention can be adjusted without departing from the spirit of the present invention, and are equally applicable to hydrogen peroxide testing in other fields, and these modifications are also within the scope of the present invention.

Claims

1. A method for detecting hydrogen peroxide using a three-mode approach with strong anti-interference and high sensitivity (colorimetric-fluorescence-upconversion luminescence), characterized in that... The specific steps are as follows: Preparation of the three-mode reagent: a. This reagent consists of 1 mM of N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide organic small molecule fluorescent probe, 0.5 mg / mL of rare earth-doped upconversion nanomaterials coated with NaYF4,Yb,Tm oleic acid, 1 mM of tetrabutylammonium hydroxide catalyst, and a mixed solvent of ethanol and ultrapure water in a volume ratio of 18:

1. 2 mM of the N-hexanoic acid-4-borate pinacol ester-1,8-naphthalimide organic small molecule fluorescent probe is added to 1 mL of ethanol and mixed thoroughly. Then, 1.25 mg / mL of rare earth-doped upconversion nanomaterials coated with NaYF4,Yb,Tm oleic acid is added to 0.8 mL of ethanol and mixed thoroughly. Next, 20 mM of the tetrabutylammonium hydroxide catalyst is added to 0.1 mL of ultrapure water and mixed thoroughly. Finally, the ethanol mixture and the ultrapure water mixture are mixed thoroughly to obtain the three-mode reagent. Detection of hydrogen peroxide using a three-mode reagent: b. Place the trimodal reagent obtained in step a into a quartz cuvette. After adding hydrogen peroxide, the solution color rapidly changes from light yellow to gold within 5 seconds. Under 468 nm blue light excitation, the fluorescence changes from green to yellow-green. Under 980 nm near-infrared light excitation, the upconversion emission changes from blue to red. When the hydrogen peroxide concentration is 0 μM-125 μM, the absorption peak intensity at 454 nm is linearly related to the hydrogen peroxide concentration, with a detection limit of 375.00 nM. When the hydrogen peroxide concentration is 0 μM-70 μM, the fluorescence emission peak intensity at 558 nm is linearly related to the hydrogen peroxide concentration, with a detection limit of 4.34 nM. When the hydrogen peroxide concentration is 0 μM-200 μM, the ratio of the upconversion emission peak intensity at 478 nm to the upconversion emission peak intensity at 646 nm is linearly related to the hydrogen peroxide concentration, with a detection limit of 94.36 nM.

2. The method for detecting hydrogen peroxide using a three-mode approach (colorimetric-fluorescence-upconversion luminescence) with strong anti-interference capabilities and high sensitivity, as described in claim 1, is characterized in that... The three-mode reagent has strong anti-interference ability in detecting hydrogen peroxide. In the presence of gold pigment, the reagent can detect hydrogen peroxide through the fluorescence channel and the upconversion luminescence channel; in the presence of yellow-green fluorescent dye, it can detect hydrogen peroxide through the colorimetric channel and the upconversion luminescence channel; and in the presence of both gold pigment and yellow-green fluorescent dye, it can detect hydrogen peroxide through the upconversion luminescence channel.

Images