Fluorescent nucleic acid silver and preparation method and application thereof

Abstract

The invention belongs to the field of nucleic acid reagent preparation and food quality detection, and particularly relates to fluorescent nucleic acid silver and a preparation method and application thereof. The fluorescent nucleic acid silver is a fluorescent DNA nano-silver cluster and is marked as DNA-AgNCs. The size of the nano-silver cluster is 3 nm. The faint yellow is displayed in a citrate buffer solution, fluorescent nucleic acid silver is excited through red light of 600 nm, high fluorescence-emission occurs at the position of 666 nm, dipyridyl ruthenium is used for contrast, and the fluorescence quantum yield is 0.2. The fluorescent nucleic acid silver and the citrate buffer solution are mixed to obtain a nucleic acid silver solution, a BSA solution is added to the nucleic acid silver solution under the condition that the molar ratio of DNA to BSA is 1:1, a BSA-DNA-AgNCs stable fluorescence system can be obtained, and the fluorescent nucleic acid silver can be applied to qualitative and quantitative analysis of the content of ferrum in milk powder.

Description

Technical field [0001] The present invention is the field of nucleic acid reagent preparation and food quality testing, which refers to a fluorescent ribinic acid silver acid and its preparation methods and applications. Background technique [0002] Iron is one of the essential trace elements of the human body. It is the formation factor of hemoglobin and muscle red protein. It has important physiological and biochemical functions.The lack of iron will lead to the reduction of the function of the immune system, anemia and other symptoms, and affect health. However, excessive absorption of iron will affect the absorption of copper and selenium elements such as copper and selenium, and cause imbalance in development. Therefore, reasonable iron supplementation is of great significance to the human body.; For infants and young children, milk powder is the most important food except breast milk. It is very important to add an appropriate amount of human body to infant milk powder to ...

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Problems solved by technology

The lack of iron will lead to symptoms such as decreased immune system function and anemia, which will affect health. However, excessive absorption of iron will affect the body's absorption of copper, selenium and other elements, resulting in imbalanced development. Therefore, reasonable iron supplementation is of great significance to the human body ;For infants and young children, milk powder is the most important food except breast milk. It is very important to add an appropriate amount of essential trace elements to infant milk powder. Due to the particularity and importance of infant food, the detection of trace elements is very important. Scientifically and systematically evaluating the content of iron in infant formula milk powder has important practical significance for evaluating the quality of milk powder and correctly guiding consumers; in the reported literature, dry ashing method is often used to process infant formula milk powder Determination of Iron Content in Milk Powder by Atomic Absorption Spectrometry[Song Longbo, Zhao Longgang, Zhao Yanwei, Chen Haihua. Determination of Iron and Zinc Element Content in Infant Milk Powder by Flame Atomic Absorption Spectrometry[J]. Anhui Agricultural Sciences, 2012,40(33):16374-16376 ], however, this detection method has the disadvantages of complicated sample preparation procedures and long time consumption; fluorescent probes with high sensitivity and high selectivity have been widely used in detection in recent years, fluorescent nucleic acid silver nanoclusters (DNA- AgNCs) stand out from many probes due to the advantages of simple synthesis method, low toxicity and strong signal [ZhaoTT, ChenQY, WangPD, ChenZP. The role of protein and nucleic acid plays an important role in biological processes. Studies have found that the combination of protein and nucleic acid can effectively improve the stability of nucleic acid silver and broaden the application of nucleic acid silver in the fields of biology and chemistry [ZhouZX, DongSJ. Protein- DNA interactions: novel approach to improve the fluorescence stability of DNA / Agnanoclusters [J].Nanoscale, 2015, 7, 1296-1300], the stable nucleic acid silver system used in food testing is rarely reported, our research will provide a new method for the qualitative and quantitative detection of iron in milk powder

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