A kind of melamine concentration fluorescence sensor and preparation method thereof

Abstract

The invention discloses a melamine concentration fluorescent sensor and a production method thereof. The melamine concentration fluorescent sensor is characterized in that electrostatic attraction acting force is utilized to prepare a positively-charged nano hydrotalcite laminate and modified negatively-charged nano silver cluster guest molecules into a composite film through a super-molecule layer-by-layer assembling method, and the fluorescent responses of the film sensor to the melamine solutions of different concentrations are inspected. The melamine concentration fluorescent sensor has the advantages that the hydrotalcite used in the melamine concentration fluorescent sensor is nontoxic, stable and good in biocompatibility, the organic laminate of the hydrotalcite is less prone to aging as compared with a polymer carrier and can be stored for a long time, the hydrotalcite laminate can keep the maximum dispersing of the guest nano silver cluster, the fluorescence quenching caused by guest molecule clustering can be prevented effectively, the optical stability of fluorescent molecules is kept, and the illumination stability of the fluorescent molecules is increased evidently; the sensor is good in selectivity on melamine and presents linear relation in a certain range.

Description

technical field

[0001] The invention belongs to the technical field of fluorescent sensor preparation, and in particular relates to an organic-inorganic composite material used as a melamine fluorescent sensor and a preparation method thereof. Background technique

[0002] In recent years, due to the advantages of high sensitivity, rich signal collection and convenient use, fluorescence sensors have not only attracted people's attention, but also developed more rapidly. By referring to the principle of homogeneous fluorescent chemical sensors used in solution, designing and fabricating thin-film fluorescent sensors is an effective way to push fluorescent sensors to practical applications. Compared with homogeneous fluorescent sensors, thin-film fluorescent sensors have unique advantages such as repeatability, maintaining the components of the system to be measured, no reagent consumption, and easy deviceization. Therefore, the study of thin-film fluorescent sensors has beco...

Examples

Embodiment 1

[0024] a. Preparation of hydrotalcite precursor: weigh 5.128g Mg(NO 3 ) 2 ·6H 2 O, 3.7513g AL (NO 3 ) 3 9H 2 O and 6.006g of urea were dissolved in 100ml of deionized water to prepare a saline solution; the solution was placed in a pressure dissolution bomb, reacted at 110°C for 12h, the product was centrifuged and washed, and 1g was added to 200ml to remove CO 2 In a flask of water, stir for 1h to swell, take 127gNaNO 3 Dissolve in 300ml to remove CO 2 Prepare the solution in water, add the sodium nitrate solution into the flask, stir for 0.5h, then slowly add 300μl of concentrated nitric acid with a pipette gun, stir for 48h, and centrifuge twice with the ethanol solution to obtain Mg after acid acid exchange. 2 Al(OH) 6 (NO 3 )·6H 2 O hydrotalcite;

[0025] b. Take the Mg obtained in step a 2 Al(OH) 6 (NO 3 )·6H 2 O hydrotalcite 0.1g is added in the flask that 100ml formamide is added, stirs 48h under nitrogen protection, obtains magnesium aluminum hydrotalcit...

Embodiment 2

[0040] a. Preparation of hydrotalcite precursor: weigh 5.128g Mg(NO 3 ) 2 ·6H 2 O, 3.7513g AL (NO 3 ) 3 9H 2 O and 6.006g of urea were dissolved in 100ml of deionized water to prepare a salt solution; the solution was placed in a high-temperature and high-pressure reactor, and reacted at 110°C for 12h, and the product was centrifuged and washed; 1g was added to 200ml to remove CO 2 In the flask of water, stir for 1h to swell, take 127gNaNO 3 Dissolve in 300ml to remove CO 2 Prepare the solution in water, add the sodium nitrate solution into the flask, stir for 0.5h, then slowly add 400μl concentrated nitric acid with a pipette gun, stir for 48h, and centrifuge twice with the ethanol solution to obtain Mg after acid acid exchange. 2 Al(OH) 6 (NO 3 )·6H 2 O hydrotalcite;

[0041] b. Take the Mg obtained in step a 2 Al(OH) 6 (NO 3 )·6H 2 O hydrotalcite 0.15g is added in the flask that 150ml formamide is added, stirs 48h under nitrogen protection, obtains magnesium a...

Embodiment 3

[0048] a. Preparation of hydrotalcite precursor: adopt urea method, weigh 5.128g Mg(NO 3 ) 2 ·6H 2 O, 3.7513g AL (NO 3 ) 3 9H 2 O and 6.006g of urea were dissolved in 100ml of deionized water to prepare a salt solution; the solution was placed in a high-temperature and high-pressure reactor, and reacted at 110°C for 12h, and the product was centrifuged and washed; the chemical formula of the prepared hydrotalcite precursor was Mg 2 Al(OH) 6 (CO 3 )·6H 2 O;

[0049] b. Take 1g of the precursor hydrotalcite prepared in step a and add 200ml to remove CO 2 In the flask of water, stir for 1h to swell, take 127gNaNO 3 Dissolve in 300ml to remove CO 2 Prepare the solution in water, add the sodium nitrate solution into the flask, stir for 0.5h, then slowly add 350ul concentrated nitric acid with a pipette gun, stir for 48h, and centrifuge twice with the ethanol solution to obtain Mg after acid acid exchange. 2 Al(OH) 6 (NO 3 )·6H 2 O hydrotalcite.

[0050] c. Take the M...

technical field

[0001] The invention belongs to the technical field of fluorescent sensor preparation, and in particular relates to an organic-inorganic composite material used as a melamine fluorescent sensor and a preparation method thereof. Background technique

[0002] In recent years, due to the advantages of high sensitivity, rich signal collection and convenient use, fluorescence sensors have not only attracted people's attention, but also developed more rapidly. By referring to the principle of homogeneous fluorescent chemical sensors used in solution, designing and fabricating thin-film fluorescent sensors is an effective way to push fluorescent sensors to practical applications. Compared with homogeneous fluorescent sensors, thin-film fluorescent sensors have unique advantages such as repeatability, maintaining the components of the system to be measured, no reagent consumption, and easy deviceization. Therefore, the study of thin-film fluorescent sensors has beco...

Examples

Embodiment 1

[0024] a. Preparation of hydrotalcite precursor: weigh 5.128g Mg(NO 3 ) 2 ·6H 2 O, 3.7513g AL (NO 3 ) 3 9H 2 O and 6.006g of urea were dissolved in 100ml of deionized water to prepare a saline solution; the solution was placed in a pressure dissolution bomb, reacted at 110°C for 12h, the product was centrifuged and washed, and 1g was added to 200ml to remove CO 2 In a flask of water, stir for 1h to swell, take 127gNaNO 3 Dissolve in 300ml to remove CO 2 Prepare the solution in water, add the sodium nitrate solution into the flask, stir for 0.5h, then slowly add 300μl of concentrated nitric acid with a pipette gun, stir for 48h, and centrifuge twice with the ethanol solution to obtain Mg after acid acid exchange. 2 Al(OH) 6 (NO 3 )·6H 2 O hydrotalcite;

[0025] b. Take the Mg obtained in step a 2 Al(OH) 6 (NO 3 )·6H 2 O hydrotalcite 0.1g is added in the flask that 100ml formamide is added, stirs 48h under nitrogen protection, obtains magnesium aluminum hydrotalcit...

Embodiment 2

[0040] a. Preparation of hydrotalcite precursor: weigh 5.128g Mg(NO 3 ) 2 ·6H 2 O, 3.7513g AL (NO 3 ) 3 9H 2 O and 6.006g of urea were dissolved in 100ml of deionized water to prepare a salt solution; the solution was placed in a high-temperature and high-pressure reactor, and reacted at 110°C for 12h, and the product was centrifuged and washed; 1g was added to 200ml to remove CO 2 In the flask of water, stir for 1h to swell, take 127gNaNO 3 Dissolve in 300ml to remove CO 2 Prepare the solution in water, add the sodium nitrate solution into the flask, stir for 0.5h, then slowly add 400μl concentrated nitric acid with a pipette gun, stir for 48h, and centrifuge twice with the ethanol solution to obtain Mg after acid acid exchange. 2 Al(OH) 6 (NO 3 )·6H 2 O hydrotalcite;

[0041] b. Take the Mg obtained in step a 2 Al(OH) 6 (NO 3 )·6H 2 O hydrotalcite 0.15g is added in the flask that 150ml formamide is added, stirs 48h under nitrogen protection, obtains magnesium a...

Embodiment 3

[0048] a. Preparation of hydrotalcite precursor: adopt urea method, weigh 5.128g Mg(NO 3 ) 2 ·6H 2 O, 3.7513g AL (NO 3 ) 3 9H 2 O and 6.006g of urea were dissolved in 100ml of deionized water to prepare a salt solution; the solution was placed in a high-temperature and high-pressure reactor, and reacted at 110°C for 12h, and the product was centrifuged and washed; the chemical formula of the prepared hydrotalcite precursor was Mg 2 Al(OH) 6 (CO 3 )·6H 2 O;

[0049] b. Take 1g of the precursor hydrotalcite prepared in step a and add 200ml to remove CO 2 In the flask of water, stir for 1h to swell, take 127gNaNO 3 Dissolve in 300ml to remove CO 2 Prepare the solution in water, add the sodium nitrate solution into the flask, stir for 0.5h, then slowly add 350ul concentrated nitric acid with a pipette gun, stir for 48h, and centrifuge twice with the ethanol solution to obtain Mg after acid acid exchange. 2 Al(OH) 6 (NO 3 )·6H 2 O hydrotalcite.

[0050] c. Take the M...

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