单核细胞增生李斯特菌的快速准确鉴定。设计了一种新的石英晶体微天平(QCM)传感器,用于单核细胞增生李斯特菌的特异性和快速检测。在QCMaptasensor中检测样品中的目标细菌之前,磁性预富集系统用于消除样品中的任何污染物。利用ATR-FTIR对所制备的磁性体系进行了表征,SEM,VSM,BET,和分析方法。Fe3O4,Fe3O4@PDA的饱和磁化强度值,Fe3O4@PDA@DAPEG颗粒分别为57.2、40.8和36.4emu/g,分别。还将相同的适体固定在整合到QCM流动池中的QCM晶体上,并用于定量检测样品中的单核细胞增生李斯特菌细胞。发现特定的适体-磁性预浓缩系统在短时间(约10分钟)内有效地捕获单核细胞增生李斯特菌细胞。Fe3O4@PDA@DA-PEG-Apt颗粒可从掺入细菌的培养基中选择性分离出高达91.8%的单核细胞增生李斯特菌。使用500ngApt/mL,磁性颗粒的固定化适体含量为5834μg/g。QCMaptasensor对目标细菌显示出非常高的分析性能范围,分别为1.0×102和1.0×107CFU/mL。检测限(LOD)和定量限(LOQ)分别为148和448CFU/mL,分别,从QCMaptasensor流动池的进料与磁性预浓缩系统的洗脱液。aptasensor的重现性大于95%。与其他李斯特菌相比,aptasensor对单核细胞增生李斯特菌非常特异(即,L.伊万诺维,L.innocua,和L.seeligeri)或其他测试细菌,如金黄色葡萄球菌,大肠杆菌,和枯草芽孢杆菌.QCMaptasensor用NaOH溶液再生,这个系统被重复使用了很多次。
A fast and accurate identification of Listeria monocytogenes. A new quartz crystal microbalance (QCM) aptasensor was designed for the specific and rapid detection of L. monocytogenes. Before detection of the target bacterium from samples in the QCM aptasensor, a magnetic pre-enrichment system was used to eliminate any contaminant in the samples. The prepared magnetic system was characterized using ATR-FTIR, SEM, VSM, BET, and analytical methods. The saturation magnetization values of the Fe3O4, Fe3O4@PDA, and Fe3O4@PDA@DAPEG particles were 57.2, 40.8, and 36.4 emu/g, respectively. The same aptamer was also immobilized on the QCM crystal integrated into QCM flow cell and utilized to quantitatively detect L. monocytogenes cells from the samples. It was found that a specific aptamer-magnetic pre-concentration system efficiently captured L. monocytogenes cells in a short time (approximately 10 min). The Fe3O4@PDA@DA-PEG-Apt particles provided selective isolation of L. monocytogenes from the bacteria-spiked media up to 91.8%. The immobilized aptamer content of the magnetic particles was 5834 µg/g using 500 ng Apt/mL. The QCM aptasensor showed a very high range of analytical performance to the target bacterium from 1.0 × 102 and 1.0 × 107 CFU/mL. The limit of detection (LOD) and limit of quantitation (LOQ) were 148 and 448 CFU/mL, respectively, from the feeding of the QCM aptasensor flow cell with the eluent of the magnetic pre-concentration system. The reproducibility of the aptasensor was more than 95%. The aptasensor was very specific to L. monocytogenes compared to the other Listeria species (i.e., L. ivanovii, L. innocua, and L. seeligeri) or other tested bacteria such as Staphylococcus aureus, Escherichia coli, and Bacillus subtilis. The QCM aptasensor was regenerated with NaOH solution, and the system was reused many times.