College of Food and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, PR China.
College of Life Science, Nanjing Normal University, Nanjing 210023, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Mar 15;249:119310. doi: 10.1016/j.saa.2020.119310. Epub 2020 Dec 7.
A smartphone-combined dual-emission ratiometric fluorescence probe for specifically and visibly detecting cephalexin was first designed. In the probe, blue-emitting fluorescent carbon dots (CDs) was synthesized and covered with a layer of silica spacer. Red-emitting fluorescent CdTe QDs (r-QDs) was grafted onto the silica nanospheres as an analytical probe. Then, the cephalexin antibody was covalent grafted to the ratio sensor to increase the selectivity. The ratio of fluorescence intensity (FL) of r-QDs and CDs was quenched with the increasing concentration of cephalexin. The detection method has good linear response in the range of 1-500 μM and the detection limit was 0.7 μM. Then portable device based on smartphone detection was constructed according to the color change under UV lamp. The detection image was obtained through the smartphone camera, and the color picker APP installed in the smartphone captured the RGB value of the image. In addition, this method was also used to determine the amount of cephalexin in milk samples with recovery of 94.1%-102.2%. These results showed that it was a portable, simple and visible method to detect cephalexin in food analysis and environmental monitoring.
首次设计了一种智能手机结合的双发射比率荧光探针，用于特异性和可视化检测头孢氨苄。在探针中，合成了发射蓝光的荧光碳点（CDs），并用二氧化硅间隔层覆盖。红色发射荧光 CdTe QDs（r-QDs）被接枝到硅纳米球上作为分析探针。然后，将头孢氨苄抗体共价接枝到比率传感器上，以提高选择性。随着头孢氨苄浓度的增加，r-QDs 和 CDs 的荧光强度（FL）比率被猝灭。检测方法在 1-500 μM 范围内具有良好的线性响应，检测限为 0.7 μM。然后根据紫外灯下的颜色变化构建了基于智能手机检测的便携式设备。通过智能手机摄像头获取检测图像，智能手机中安装的颜色选择器 APP 捕获图像的 RGB 值。此外，该方法还用于测定牛奶样品中头孢氨苄的含量，回收率为 94.1%-102.2%。这些结果表明，该方法是一种用于食品分析和环境监测中检测头孢氨苄的便携式、简单、可视化的方法。
