基于Fe3O4@Au模拟酶智能手机比色法检测牛奶中尿酸的研究

Determination of uric acid in milk by Fe3O4@Au smartphone colorimetric method

目的 利用Fe3O4@Au的过氧化物模拟酶活性构建检测牛奶中过量尿酸的智能手机比色传感器。方法 通过单因素正交实验获取模拟酶比色和智能手机比色的最佳检测条件,利用紫外分光光度法和智能手机比色法测定不同浓度的尿酸溶液,同时评估体系的灵敏度、抗干扰性和稳定性。结果 Fe3O4@Au最优催化体系为反应温度60℃,反应时间50min及Fe3O4@Au添加量0.015g。智能手机比色体系最优相机分辨率为12 MP,光圈f值为4.00 mm,感光度(photosensibility, ISO)值为800及快门速度为0.002 s;基于智能手机比色法检测尿酸最优条件下,尿酸浓度在0.075~7.500mmol/L范围内显现出良好的线性关系,工作曲线为Y1=-47.362X1+494.35(r2=0.9918),检出限为0.043μmol/L。在实际样品检测中,加标回收率在96.90%~112.81%之间,相对标准偏差均低于4.00%。结论 基于Fe3O4@Au模拟酶活性建立的智能手机比色检测体系,具有极高的灵敏度,良好的抗干扰性和稳定性,该研究成果将为尿酸等食品成分的分析检测提供一条新的渠道。

Objective To construct a smartphone colorimetric sensor for the detection of excess uric acid in milk based on Fe3O4@Au peroxide-mimetic enzyme activity.Methods The optimal assay conditions for mock enzyme colorimetry and smartphone colorimetry was obtained using a one-way orthogonal test.Different concentrations of uric acid solutions were determined based on ultraviolet spectrophotometry and smartphone colorimetry,and the sensitivity,interference resistance and stability of the system were also evaluated.Results Equivalent conditions for the Fe3O4@Au catalytic system were a reaction temperature of 60℃,a reaction time of 50 min and Fe3O4@Au addition of 0.015 g.The colorimetric system for smartphones with an optimal camera resolution of 12 MP,an aperture f value of 4.00 mm,a sensitivity photosensibility(ISO)value of 800 and shutter speed was 0.002 s.Under the optimal conditions,the smartphone colorimetric assay for uric acid showed good linearity in the range of 0.075‒7.500 mmol/L,with the working curve of Y=‒47.362X+494.35,r 2=0.9918,and the limit of detection was 0.043μmol/L.The calibration recoveries of the actual samples spiked ranged from 96.90%to 112.81%with the relative standard deviations all below 4.00%.Conclusion The smartphone colorimetric detection system based on Fe3O4@Au simulated enzyme activity has high sensitivity,which has excellent anti-interference and stability.The research results provides a new idea for the analysis and detection of food components such as uric acid.