Carbon quantum dot/aurum cluster ratiometric fluorescent probe for detection of cadmium ion and ascorbic acid

A ratiometric fluorescent probe, ascorbic acid technology, applied in the field of fluorescent sensing, can solve the problems of high cost and weak luminescence stability, and achieve high selectivity, sensitivity, and high detection accuracy

Inactive Publication Date: 2016-10-26
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] In order to solve the problems of high cost and weak luminescence stability of the existing ratiometric fluorescent probes used for the detection of cadmium ions and ascorbic acid, the present invention provid

Method used

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  • Carbon quantum dot/aurum cluster ratiometric fluorescent probe for detection of cadmium ion and ascorbic acid
  • Carbon quantum dot/aurum cluster ratiometric fluorescent probe for detection of cadmium ion and ascorbic acid
  • Carbon quantum dot/aurum cluster ratiometric fluorescent probe for detection of cadmium ion and ascorbic acid

Examples

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Embodiment 1

[0035] A method for preparing the carbon quantum dot / gold nanocluster ratio fluorescent probe of the present invention comprises the steps:

[0036] Step 1. Preparation of carbon quantum dots: ultrasonically dissolve 2.673g of alanine and 0.466g of histidine in 30.0mL of ultrapure water, and then transfer the mixed solution into a polytetrafluoroethylene autoclave (model 50.0mL) placed in a blast-type heating oven, hydrothermally reacted at 200°C for 6 hours, and cooled naturally to room temperature after the reaction to obtain a dark green transparent liquid, which was put into a dialysis bag with a molecular weight cut-off of 1000 and dialyzed in double-distilled water for 24 hours to remove untreated The precursor of the reaction was removed by rotary evaporation at 45°C to prepare CQDs;

[0037] Step 2, preparation of amidated carbon quantum dots: disperse 5 mg of CQDs obtained in step 1 and 20 μL of ammonia (28 wt %) into 1.5 mL of absolute ethanol, add 10 μL of 3-aminopr...

Embodiment 2

[0041] A method for preparing the carbon quantum dot / gold nanocluster ratio fluorescent probe of the present invention comprises the steps:

[0042] Step 1, preparation of carbon quantum dots: ultrasonically dissolve 2.138g of alanine and 0.466g of histidine in 30.0mL of ultrapure water, and other conditions are the same as step 1 of Example 1;

[0043] Step 2, preparation of amidated carbon quantum dots: same as step 2 of Example 1;

[0044] Step 3, preparation of gold nanoclusters (AuNCs): same as step 3 of Example 1;

[0045] Step 4. Preparation of carbon quantum dots / gold nanoclusters (CQDs / AuNCs): Take 800 μL of the 2.0 mg / mL MUA-modified AuNCs solution prepared in step (3) and diffuse into 1.5 mL of HEPES buffer, and sonicate evenly. Freshly prepare an aqueous solution containing 10mM 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and 20mM N-hydroxysuccinimide, add 100μL EDC / NHS mixed solution The above 1.5mL AuNCs solution was magnetically stirred f...

Embodiment 3

[0047] A method for preparing the carbon quantum dot / gold nanocluster ratio fluorescent probe of the present invention comprises the steps:

[0048] Step 1, preparation of carbon quantum dots: ultrasonically dissolve 4.2763g of alanine and 0.466g of histidine in 30.0mL of ultrapure water, and other conditions are the same as step 1 of Example 1;

[0049] Step 2, preparation of amidated carbon quantum dots: same as step 2 of Example 1;

[0050] Step 3, preparation of gold nanoclusters (AuNCs): same as step 3 of Example 1;

[0051] Step 4. Preparation of carbon quantum dots / gold nanoclusters (CQDs / AuNCs): Take 200 μL of the 2.0 mg / mL MUA-modified AuNCs solution prepared in step (3) and diffuse into 1.5 mL of HEPES buffer, and sonicate evenly. Freshly prepare an aqueous solution containing 10 mM 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and 40 mM N-hydroxysuccinimide, add 100 μL EDC / NHS mixed solution The above 1.5mL AuNCs solution was magnetically stirr...

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Abstract

The invention discloses a carbon quantum dot/aurum cluster ratiometric fluorescent probe for detection of cadmium ion and ascorbic acid. A preparation method comprises the following steps: preparing CQDs (Carbon Quantum Dots) from alanine and histidine through a one-step hydrothermal method; performing amino-functionalization on the CQDs by using 3-aminopropyltriethoxysilane, wherein the CQDs which are subjected to the amino-functionalization serve as a reference chromophore; reducing chloroauric acid through sodium borohydride by taking 11-sulfydryl undecanoic acid as a surfactant to obtain MUA-modified AuNCs (Aurum Nano Clusters), wherein the MUA-modified AuNCs serve as a main fluorophore of the ratiometric fluorescent probe; finally, coupling the CQDs and the AuNCs through an amidation reaction to obtain the CQDs/AuNCs ratiometric fluorescent probe. On the basis of static quenching and inter-filtering effects, the fluorescence of the CQDs/AuNCs can be quenched by Cd<2+>; the invention discloses the application of the CQDs/AuNCs ratiometric fluorescent probe in Cd<2+> detection. The fluorescence of the CQDs/AuNCs which is quenched by the Cd<2+> can be recovered by the ascorbic acid, so that the ratiometric fluorescent probe can also be used for the detection of AA (Ascorbic Acid). The ratiometric fluorescent probe disclosed by the invention has the lower detection limit of 32.5 nM to the Cd<2+>, has the lower detection limit of 0.105 muM to the AA, and has an application value in the detection of the cadmium ion and the ascorbic acid.

Description

technical field [0001] The invention belongs to the technical field of fluorescent sensing, in particular to a carbon quantum dot / gold cluster ratio fluorescent probe for detecting cadmium ions and ascorbic acid and a preparation method thereof. Background technique [0002] Ratio-type fluorescent probes have a main fluorophore and a reference chromophore, and the two emission peaks are separated. The ratio of fluorescence intensity can provide internal correction of environmental interference and eliminate fluctuations in excitation light intensity, improving the accuracy of quantitative analysis. Breakthrough The probe based on a single fluorescence intensity is easily affected by the detection substrate, photobleaching and other shortcomings, and at the same time avoids the interference of probe concentration, polarity, environmental pH and other factors, and solves the dilemma of false positive consequences. It has received great attention in recent years. [0003] Cadm...

Claims

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Application Information

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IPC IPC(8): C09K11/65G01N21/64
CPCC09K11/65G01N21/6402
Inventor 单丹朱容慧牛文军华艳李怡萱宗丽萍
Owner NANJING UNIV OF SCI & TECH
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