Hao Li, Xue Li, Huang Fengchun, Cai Gaozhe, Qi Wuzhen, Zhang Miao, Han Qing'an, Wang Zengli, Lin Jianhan
Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing 100083, China.
Key Laboratory of Modern Precision Agriculture System Integration Research, Ministry of Education, China Agricultural University, Beijing 100083, China.
Micromachines (Basel). 2020 Mar 9;11(3):281. doi: 10.3390/mi11030281.
Screening of foodborne pathogens is an effective way to prevent microbial food poisoning. A microfluidic biosensor was developed for rapid and sensitive detection of Typhimurium using quantum dots (QDs) as fluorescent probes for sensor readout and manganese dioxide nanoflowers (MnO NFs) and as QDs nanocarriers for signal amplification. Prior to testing, amino-modified MnO nanoflowers (MnO-NH NFs) were conjugated with carboxyl-modified QDs through EDC/NHSS method to form MnO-QD NFs, and MnO-QD NFs were functionalized with polyclonal antibodies (pAbs) to form MnO-QD-pAb NFs. First, the mixture of target Typhimurium cells and magnetic nanoparticles (MNPs) modified with monoclonal antibodies (mAbs) was injected with MnO-QD-pAb NFs into a microfluidic chip to form MNP-bacteria-QD-MnO complexes. Then, glutathione (GSH) was injected to dissolve MnO on the complexes into Mn, resulting in the release of QDs. Finally, fluorescent intensity of the released QDs was measured using the fluorescent detector to determine the amount of . A linear relationship between fluorescent intensity and bacterial concentration from 1.0 × 10 to 1.0 × 10 CFU/mL was found with a low detection limit of 43 CFU/mL and mean recovery of 99.7% for in spiked chicken meats, indicating the feasibility of this biosensor for practical applications.
筛查食源性病原体是预防微生物食物中毒的有效方法。开发了一种微流控生物传感器，用于快速灵敏地检测鼠伤寒沙门氏菌，使用量子点（QDs）作为传感器读数的荧光探针，以及二氧化锰纳米花（MnO NFs）作为QDs的纳米载体用于信号放大。在测试之前，通过EDC/NHSS方法将氨基修饰的MnO纳米花（MnO-NH NFs）与羧基修饰的QDs偶联形成MnO-QD NFs，并用多克隆抗体（pAbs）对MnO-QD NFs进行功能化处理以形成MnO-QD-pAb NFs。首先，将目标鼠伤寒沙门氏菌细胞与用单克隆抗体（mAbs）修饰的磁性纳米颗粒（MNPs）的混合物与MnO-QD-pAb NFs注入微流控芯片中，形成MNP-细菌-QD-MnO复合物。然后，注入谷胱甘肽（GSH）将复合物上的MnO溶解为Mn，从而释放出QDs。最后，使用荧光检测器测量释放的QDs的荧光强度，以确定[原文此处未提及具体物质]的量。在加标的鸡肉中，荧光强度与细菌浓度在1.0×10至1.0×10 CFU/mL之间呈线性关系，检测限低至43 CFU/mL，平均回收率为99.7%，表明该生物传感器在实际应用中的可行性。
