Microfluidic two-aqueous phase droplet flow method for simple and rapid detection of urea and device thereof

Abstract

The invention relates to a microfluidic two-aqueous phase droplet flow method for simple and rapid detection of urea and a device thereof. The method includes the steps of: taking a mixed solution ofa neutral red indicator, a to-be-detected sample and polyethylene glycol as the internal aqueous phase, and adopting a urease and glucan mixed solution as the external aqueous phase. According to themicrofluidic device, the shearing action of the two-phase fluid is utilized to form 10-30 nano-liters of two-aqueous phase droplets, enzymatic reaction is carried out on urea and urease in the droplets and at the interface, the product ammonium carbonate enables the neutral red indicator in the droplets to discolor, and according to the discoloration degree, whether the sample contains urea can bejudged and the urea content can be analyzed, one sample detection only needs 10-20sec, and the enzyme-containing external aqueous phase solution can be recycled. The method provided by the inventionhas the advantages of wider detection range, low operation cost, simplicity, rapidity and environmental friendliness.

Description

technical field [0001] The invention relates to a chemical detection method, especially a simple and fast urea detection method. Background technique [0002] In the production of industrial, agricultural and medical industries, such as water quality, soil, food, medicine and blood, it is necessary to detect the content of urea. Therefore, it is of great significance to detect the urea content. Routine urea detection methods in the laboratory, such as the Kjeldahl method, are used to detect the total nitrogen content, and cannot exclude the influence of other nitrogen-containing compounds to specifically measure the urea content in the sample; at the same time, commercially available common urea determination instruments The general measurement range is 0-0.2mg·mL-1, which is not suitable for the measurement of high-concentration urea; and they all have the disadvantages of long time consumption, expensive instruments, large amount of chemical reagents, etc., and inevitably...

AI Technical Summary

Problems solved by technology

In 1986, Gao Shizhong et al. [1] proposed a method for the reaction of diacetyl monoxime and urea to form a colored compound (see Gao Shizhong, Lv Jiefang, Lv Yongchang. Rapid qualitative analysis of urea and cow urine in milk [J]. China Dairy Industry, 1986(3):14-16.), the presence or absence of urea is judged by whether it develops color, but diacetyl monoxime does not only react with urea to develop color, but also reacts with its metabolite citrulline. The measurement method does not exclude the influence of citrulline on the urea concentration

In 2009, Yang Shuiyun et al. [2] invented a test paper for detecting urea content (see Yang Shuiyun, Ma Xiaoming, Xu Fan, etc. Preparation of urea detection test paper in dairy products and urea detection method: CN101398386[P].2009.), The process of preparing test paper is relatively complicated and difficult to preserve, and it is more susceptible to environmental factors such as pH value and humidity during preservation and on-site testing.

This method can only be compared with the positive control group, and the operation process is complicated, the amount of reagents used in the test is large, and it is easy to cause pollution to the environment

[0004] It can be seen that there is still a lack of a fast, simple, low reagent consumption, economical and practical analysis method to determine whether urea is contained in the sample and to obtain the urea content in the market.

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