CN110376040A - A kind of g-C3N4@MnO2The preparation method and applications of compound system - Google Patents

Abstract

The invention discloses a kind of g-C₃N₄@MnO₂The preparation method and applications of compound system, by preparing g-C₃N₄And MnO₂Nano flake, and by the g-C after ultrasound₃N₄Aqueous solution is made in powder, takes MnO₂Aqueous solution is added thereto, and is configured to g-C₃N₄@MnO₂Composite solution obtains compound system.The compound system can be used for detecting glutathione, due to MnO₂Nanometer sheet has compared with strong oxidizing property, after the glutathione with reproducibility is added, MnO₂It is reduced and is decomposed into Mn²⁺, to make g-C₃N₄The fluorescence being quenched restores.According to the concentration that glutathione is added, the fluorescence signal of respective strengths can detecte.

Description

A kind of g-C3N4@MnO2The preparation method and applications of compound system

Technical field

The invention belongs to glutathione detection technique fields, and in particular to a kind of g-C₃N₄@MnO₂The preparation side of compound system Method and its application.

Background technique

Glutathione (GSH) participates in internal tricarboxylic acid cycle and sugar as a kind of intracellular important regulatory metabolites matter Metabolism, and a variety of enzymes can be activated, such as sulfydryl (SH) enzyme-coenzyme, to promote carbohydrate, fat and protein metabolism.GSH molecule Feature is active sulfydryl (- SH), is most important function group, may participate in a variety of important biochemical reactions of body, protection Internal important enzyme protein sulfhydryl is not oxidized, inactivates, and guarantees that energetic supersession, cell utilize.Meanwhile by sulfydryl with it is intracorporal Free radical combines, and directly radical reduction can be made at acidic materials, to accelerate the excretion of free radical, and to free radical resisting counterweight Want the damage of internal organs.The discovery such as Armstrong, the reduction of GSH content is a kind of potential apoptosis early stage activation signal, is then produced Raw oxygen radical promotes apoptosis, it is even more important that if glutathione content horizontal abnormality in vivo, can prompt Body suffers from disease, such as HIV, parkinson's syndrome, inflammation, hepatic injury etc. can primosome glutathion inside content it is different Often.Therefore efficient, accurate detection glutathione, verifies its function in physiology, pathologically and is of great significance.Therefore to thin The measurement of GSH content intracellular has important theory and realistic meaning.

Glutathione detection method is more, and more commonly used has iodimetric titration, sodium nitroprusside method, surface-enhanced Raman Scattering method (SERS), electrochemical analysis, fluorescence method, alloxan method and high performance liquid chromatography.Although related gluathione at present The existing many reports of the trace analysis methods of peptide, but the disadvantages of such as sensitivity is not high, and anti-interference ability is insufficient is also deposited, how Develop quantitative and real-time monitoring of easier, quick, the highly sensitive detection method for glutathione, be still one very Big challenge.

Summary of the invention

In view of the problems of the existing technology the present invention, passes through preparation MnO₂Nano flake, with g-C₃N₄Effect forms g- C₃N₄@MnO₂Nano composite system passes through fluorescent method quantitative detection glutathione.

The present invention is realized especially by following technical scheme:

A kind of g-C₃N₄@MnO₂The preparation method of compound system, comprising the following steps:

1)g-C₃N₄Preparation

It weighs melamine and is warming up to 550 DEG C of holdings 4 hours, be cooled to 60 DEG C hereinafter, the grinding of calcined sample, obtains Faint yellow g-C₃N₄Powder, it is spare；

2)MnO₂The preparation of nanometer sheet

H is added into tetramethylammonium hydroxide aqueous solution₂O₂, stir and be added to MnCl₂In solution, it is small to be stirred to react 14 When, obtained dark brown product is centrifuged 20min, and the product after washing is placed in drying in baking oven, obtains dry MnO₂Nanometer thin Piece；

3)g-C₃N₄@MnO₂The preparation of composite solution

G-C after weighing ultrasound₃N₄Aqueous solution is made in powder, takes MnO₂Aqueous solution is added thereto, and is configured to g-C₃N₄@MnO₂ Composite solution stores for future use.

Further, heating rate is 10 DEG C/min in step (1).

Further, centrifugal condition is 2000r/min in step (2), and drying condition is 60 DEG C.

Further, MnO in step (3)₂The concentration of aqueous solution is 1mg/mL.

Further, g-C in composite solution described in step (3)₃N₄Concentration is 0.4mg/mL, the MnO₂Concentration For 0.8mg/mL.

In another aspect of this invention, g-C is prepared in above-mentioned preparation method₃N₄@MnO₂Composite solution is also of the invention Within protection scope.

In another aspect of the present invention, the g-C₃N₄@MnO₂Application of the composite solution in detection glutathione.

Preferably, pass through fluorescent method quantitative detection glutathione.

The invention has the benefit that

The present invention makes full use of the semiconductor material g-C that can emit strong fluorescence₃N₄And there is good ultraviolet visible light to inhale The MnO of receipts₂The property of two-dimensional nano piece, simple method are prepared for g-C₃N₄@MnO₂Nano composite system.MnO₂Nanometer sheet can be right g-C₃N₄Fluorescence generate quenching effect, once contain reductive glutathione in detection architecture, g-C₃N₄Fluorescence can be extensive It is multiple, it realizes to the highly sensitive of glutathione and selectively measures.It is sensitive to solve the related glutathione detection reported in the past The problems such as degree is not high, and anti-interference ability is insufficient.It can be easier, quick, highly sensitive for the quantitative and real-time of glutathione Monitoring.

Detailed description of the invention

Fig. 1 is MnO₂Nanometer sheet transmission electron microscope picture；

Fig. 2 is that glutathione restores g-C₃N₄@MnO₂Compound system fluorescence principle figure；

Fig. 3 is the fluorescence response figure of feasibility Experiment；Wherein (a) MnO₂；(b)g-C₃N₄+MnO₂；(c)g-C₃N₄+MnO₂+ 1mg mL^-1GSH；(d)g-C₃N₄+MnO₂+2mg mL^-1GSH；(e)g-C₃N₄；

Fig. 4 is influence of the different ultrasonic times to fluorescence intensity

Fig. 5 is g-C₃N₄Electron microscope；A is not ultrasonic, and B ultrasound sound 8 hours；

Fig. 6 is influence of the different pH to fluorescence intensity；

Fig. 7 is the MnO of various concentration₂To the influence diagram of fluorescence intensity；

Fig. 8 is that glutathione time corresponding fluorescence intensity figure is added；

Fig. 9 is the fluorescence intensity figure of system in the presence of object and chaff interferent；

Figure 10 is g-C in the presence of metal ion₃N₄The fluorescence intensity figure of solution；

Figure 11 is the Detection of Stability figure that continuous 10 days glutathione fluorescence restores.

Specific embodiment

Below in conjunction with specific embodiment of the present invention, technical solution of the present invention is clearly and completely described, is shown So, described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.Based on the reality in the present invention Example is applied, every other embodiment obtained by those of ordinary skill in the art without making creative efforts all belongs to In the scope of protection of the invention.

Embodiment 1g-C₃N₄@MnO₂Nano composite system

1)g-C₃N₄Preparation

It accurately weighs 8g melamine to be placed in crucible, is put into Muffle furnace, be warming up to 550 DEG C with the rate of 10 DEG C/min, After being kept for 4 hours under the conditions of 550 DEG C, 60 DEG C are naturally cooled to hereinafter, the grinding of calcined sample, finally obtains faint yellow g- C₃N₄Powder, it is spare.

2)MnO₂The preparation of nanometer sheet

2.18g tetramethylammonium hydroxide solid and 0.60g manganous chloride solid are weighed with assay balance respectively, respectively by it It is dissolved in the deionized water of 25mL and 15mL.A certain amount of 30% is added into configured tetramethyl ammonium hydroxide solution H₂O₂Solution is quickly adding into MnCl in the case where continuously stirring₂In solution, dark brown is immediately become in the short time.Then, The reaction is continuously stirred overnight 14 hours, by obtained dark brown product centrifugation (2000r/min) 20 minutes, respectively with methanol and Deionized water is washed 3 times.Product after washing is placed in 60 DEG C of dryings in baking oven, spare after collection, obtains dry MnO₂Nanometer Thin slice (such as Fig. 1) about 0.25g.

Take 10mg MnO₂Nano flake is dissolved in the deionized water of 10mL (1mg mL^-1), it is sonicated to be dispersed 1mg mL is made in object^-1MnO₂Solution for standby.

3)g-C₃N₄@MnO₂The preparation of composite solution

Accurately weigh the g-C that ultrasonic time is 8 hours₃N₄Powder 15mg is in 50mL centrifuge tube and 7.5mL deionization is added Water is configured to 2mg mL^-1G-C₃N₄Then solution takes 1mg mL^-1MnO₂Solution 30mL is added thereto, and is configured to g-C₃N₄@ MnO₂Composite solution makes g-C in solution₃N₄Concentration is 0.4mg mL^-1、MnO₂Concentration is 0.8mg mL^-1, store for future use.

Embodiment 2 detects glutathione

Based on g-C₃N₄@MnO₂The experimental principle for quantitative detection glutathione of compound system is as shown in Figure 2.g-C₃N₄ It is a kind of stable novel metalloid catalysis material, under the excitation of certain wavelength light, in the wave-length coverage of 430~550nm, Stronger fluorescence intensity can be emitted.Due to MnO₂Absorption spectrum and g-C₃N₄Emission spectrum partly overlap, when by g-C₃N₄ With MnO₂When nanometer sheet mixes, it may occur that fluorescence resonance energy transfer (FRET) quenches g-C₃N₄Fluorescence.Due to MnO₂Nanometer sheet has compared with strong oxidizing property, after the glutathione with reproducibility is added, MnO₂It is reduced and is decomposed into Mn²⁺, To make g-C₃N₄The fluorescence being quenched restores.According to the concentration that glutathione is added, the fluorescence letter of respective strengths can detecte Number.

In order to prove that glutathione can make g-C₃N₄@MnO₂Compound system fluorescence is extensive.With 1mg mL^-1MnO₂Solution, pH are 6.5 Tirs-HCl buffer solution, 1mg mL^-1G-C₃N₄Solution, 10mg mL^-1Glutathione solution prepare respectively a, b, C, five parts of solution of d, e are 5nm, transmite slit 5nm, voltage 650V, the fluorescence parameter of excitation wavelength 365nm in exciting slit Lower carry out fluoremetry, obtains result shown in following Fig. 3.As can be seen from Figure 3, g-C₃N₄Fluorescence intensity it is very high (e), when its with MnO₂(a) when mixing, fluorescence intensity is substantially reduced, g-C₃N₄Fluorescence by MnO₂It quenches (b).And when the body is added in glutathione When being, MnO₂It is Mn by glutathione reduction²⁺, to release g-C₃N₄, system fluorescence is made to restore (c), (d).It is demonstrated experimentally that With glutathione to g-C₃N₄@MnO₂It is feasible that compound system, which carries out fluorescence recovery, and the concentration of glutathione is bigger, to body The fluorescence recovery effects of system are better.

The optimization of 3 testing conditions of embodiment

1)g-C₃N₄Ultrasonic time optimization

g-C₃N₄The size of sample particle has larger impact to fluorescence intensity, for the optimum reaction conditions for finding sample, experiment It is middle special by g-C₃N₄Sample is divided into 5 parts, respectively ultrasound 0h, 4h, 6h, 8h, 10h, and pays attention to maintaining the water temperature in ultrasonic cleaner At 30 DEG C or less.After treatment, it obtains drying product accordingly, and is dissolved in being configured to certain density g-C in water₃N₄ Solution for standby.Acquired solution is diluted to 0.2mg mL^-1Fluoremetry is carried out respectively, and (error bar representative is surveyed three times as shown in Figure 4 The standard deviation of amount).It can be seen from the figure that with the growth of ultrasonic time, fluorescent intensity also increases, and ultrasound 8 Hour and 10 hours fluorescence intensities are not much different, so choosing 8 hours g-C of ultrasound₃N₄It is test as sample.In addition, can Can be clearly seen that the g-C not being ultrasonically treated from electron microscope 5₃N₄Thickness of sample is larger (A), and after 8 hours ultrasounds g-C₃N₄Thin slice becomes thinner (B).

2) pH optimizes

In general, pH value is affected to fluorescence signal, when pH value is excessive or too small in system, the fluorescence observed Signal is all smaller, for the sensitivity for improving experiment, maintains g-C in an experiment₃N₄Concentration is 0.2mg mL^-1The pH of solution is carried out Optimization.As in Fig. 6 it is found that with pH value increase, fluorescence intensity first increases and then decreases, when pH is 6.5, the fluorescence that detects Maximum intensity, therefore, we are using pH value 6.5 as the Optimal pH next tested.

3)MnO₂Concentration optimization

MnO₂Nano flake adsorbs g-C₃N₄Lead to fluorescent quenching, but as addition MnO₂When concentration is too small, fluorescent quenching Effect is unobvious, and works as MnO₂Concentration is excessive, can make MnO₂Nanometer sheet is remaining, and fluorescence restores when being unfavorable for that glutathione is added Measuring, so to MnO₂Concentration optimize and be very important.G-C is maintained in an experiment₃N₄Concentration is 0.2mg mL^-1, the MnO of various concentration is added₂Carry out fluoremetry.It can be seen from figure 7 that with MnO in solution₂The increase of concentration, g-C₃N₄Fluorescence intensity gradually decrease.Work as MnO₂Concentration is greater than 0.4mg mL^-1When, fluorescence intensity is lower and variation is unknown It is aobvious.To keep the fluorescence intensity change of experiment obvious, with 0.4mg mL^-1Concentration be subsequent experimental in MnO₂Concentration examined It surveys.

4) reaction time optimizes

Glutathione is added to g-C₃N₄@MnO₂When in compound system, fluorescence intensity can become with the time is added Change, the addition time is shorter, and fluorescence restores incomplete；And it is added that the time is too long, the efficiency that will lead to detection reduces.Therefore, to paddy The sweet peptide of Guang restores MnO₂Reaction time is optimized.Pipette the g-C of certain volume₃N₄@MnO₂Composite solution injects 2mL centrifugation Guan Zhong, then it is separately added into the 10mg mL of certain volume^-1Glutathione solution and pH value be 6.5 Tirs-HCl buffer solution, Make the concentration 1.0mg mL of the glutathione in mixed solution^-1、g-C₃N₄Concentration is 0.2mg mL^-1、MnO₂Concentration is 0.4mg mL^-1, every the solution fluorescence situation of measurement in five minutes, as a result as shown in Figure 8.It can be seen from the figure that fluorescence intensity is at any time Between growth and enhance that the fluorescence intensity in 30min is basicly stable, therefore select 30min for the most suitable reaction time.

The performance evaluation of the detection glutathione of embodiment 4

1) selectivity analysis

In actual sample may there are many chaff interferents to exist, it is therefore desirable to consider that there may be chaff interferents to detection architecture Therefore the influence of fluorescence intensity is separately added into the molten of the starch of same concentrations, glucose, glutamic acid, glycine and glutathione Liquid, and fluorescence measurement is carried out under the same conditions.It can be seen in figure 9 that compared with the fluorescence signal that glutathione is added, The fluorescence intensity of system is smaller in the presence of his chaff interferent, almost can be ignored.So the fluorescence sense system is to gluathione Peptide has good selectivity.

2) metal ion disturbance is tested

In view of, there may be each metal ion species, this experiment is subsequent in g-C in actual sample₃N₄One is added in solution Determine the Na of concentration⁺、K⁺、Cu²⁺、Fe²⁺、Zn²⁺、Mg²⁺Carry out fluorescence detection.It can be seen from fig. 10 that being added glimmering when metal ion Intensity variation is little, illustrates the presence of metal ion to g-C₃N₄The fluorescence intensity of solution influences very little, can be ignored.

3) stability analysis

In order to verify the system to the stability of glutathione test experience, we are respectively 1mg mL to concentration is added^-1 With 2mg mL^-1The fluorescence system of glutathione carried out continuous 10 days progress fluorescent strength determinings.It can be seen from fig. 11 that The glutathione of two kinds of concentration makes compound system fluorescence recovery strength tend towards stability in a certain range respectively, it was demonstrated that this experiment side The stability of method is preferable.

It although an embodiment of the present invention has been shown and described, for the ordinary skill in the art, can be with Understand without departing from the principles and spirit of the present invention can to these examples carry out it is a variety of variation, modification, replacement and Modification, the scope of the present invention is defined by the appended.

Claims (8)

1. a kind of g-C₃N₄@MnO₂The preparation method of compound system, which comprises the following steps:

1)g-C₃N₄Preparation

It weighs melamine and is warming up to 550 DEG C of holdings 4 hours, be cooled to 60 DEG C hereinafter, the grinding of calcined sample, obtains yellowish Color g-C₃N₄Powder, it is spare；

2)MnO₂The preparation of nanometer sheet

H is added into tetramethylammonium hydroxide aqueous solution₂O₂, stir and be added to MnCl₂In solution, it is stirred to react 14 hours, obtains The dark brown product arrived, is centrifuged 20min, and the product after washing is placed in drying in baking oven, obtains dry MnO₂Nano flake；

3)g-C₃N₄@MnO₂The preparation of composite solution

G-C after weighing ultrasound₃N₄Aqueous solution is made in powder, takes MnO₂Aqueous solution is added thereto, and is configured to g-C₃N₄@MnO₂It is compound Solution stores for future use.

2. a kind of g-C according to claim 1₃N₄@MnO₂The preparation method of compound system, which is characterized in that step (1) Middle heating rate is 10 DEG C/min.

3. a kind of g-C according to claim 1₃N₄@MnO₂The preparation method of compound system, which is characterized in that step (2) Middle centrifugal condition is 2000r/min, and drying condition is 60 DEG C.

4. a kind of g-C according to claim 1₃N₄@MnO₂The preparation method of compound system, which is characterized in that step (3) Middle MnO₂The concentration of aqueous solution is 1mg/mL.

5. a kind of g-C according to claim 1₃N₄@MnO₂The preparation method of compound system, which is characterized in that step (3) Described in composite solution in g-C₃N₄Concentration is 0.4mg/mL, the MnO₂Concentration is 0.8mg/mL.

6. the g-C that preparation method described in claim 1 is prepared₃N₄@MnO₂Compound system.

7. g-C as claimed in claim 6₃N₄@MnO₂Application of the compound system in detection glutathione.

8. application according to claim 7, which is characterized in that pass through fluorescent method quantitative detection glutathione.