The rapid detection of antibiotic residual in everyday life is very important for food safety. In order to realize the on-site and visual detection of antibiotic, a POCT method was established by using digital image colorimetry based on smartphone. Streptomycin was taken as the analyte model of antibiotics, streptomycin aptamer preferentially recognized analyte, and the excess aptamer hybridized with the complementary DNA to form the dsDNA. SYBR Green I combined with the dsDNA and then emitted obvious green fluorescence, thus the fluorescence intensity decreased with the increasing of streptomycin concentration. Then a smartphone-based device was constructed as the fluorescence readout. The smartphone camera acquired the images of the fluorescence derived from the samples, and the Touch Color APP installed in smartphone read out the RGB values of the images. There was a linear relationship between the G values and the streptomycin concentrations in the range of 0.1–100 µM. The detection limit was 94 nM, which was lower than the maximum residue limit defined by World Health Organization. The POCT method was applied for determining streptomycin in chicken and milk samples with recoveries in 94.1–110%. This method had the advantages of good selectivity, simple operation and on-site visualization.

快速检测日常生活中残留的抗生素对食品安全非常重要。为了实现对抗生素的现场和视觉检测，通过基于智能手机的数字图像比色法建立了POCT方法。以链霉素为抗生素的分析物模型，链霉素适体优先识别的分析物，过量的适体与互补DNA杂交形成dsDNA。SYBR Green I与dsDNA结合后发出明显的绿色荧光，因此随着链霉素浓度的增加，荧光强度降低。然后，将基于智能手机的设备构建为荧光读数。智能手机摄像头获取了来自样本的荧光图像和Touch Color安装在智能手机中的APP读出图像的RGB值。G值和链霉素浓度在0.1–100 µM之间存在线性关系。检出限为94 nM，低于世界卫生组织规定的最大残留限量。POCT方法用于测定鸡肉和牛奶样品中的链霉素，回收率为94.1–110％。该方法具有选择性好，操作简单和现场可视化的优点。