Pang Pengfei, Huang Sijing, Cai Qingyun, Yao Shouzhuo, Zeng Kefeng, Grimes Craig A
State Key Laboratory of Chemo/Biosensing and Chemometrics, Department of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
Biosens Bioelectron. 2007 Sep 30;23(2):295-9. doi: 10.1016/j.bios.2007.07.004. Epub 2007 Jul 21.
This paper describes the real-time quantification of Pseudomonas aeruginosa (P. aeru) concentrations using a wireless magnetoelastic sensing device. The sensor is fabricated by coating a magnetoelastic ribbon with a polyurethane protecting film. In response to an externally applied time varying magnetic field, the magnetoelastic sensor vibrates at a resonance frequency that can be remotely determined by monitoring the magnetic flux emitted by the sensor. The resonance frequency changes in response to properties changes of a liquid culture medium and bacteria adhesion to the sensor as P. aeru consumes nutrients from the culture medium in growth and reproduction. The effects of properties (conductivity, viscosity, mass) are investigated with quartz crystal microbalance (QCM), microscopy imaging, and conductivity measurement. Using the described technique we are able to directly quantify P. aeru concentrations of 10(3) to 10(8)cells/ml, with a detection limit of 10(3)cells/ml at a noise level of approximately 20 Hz. The lack of any physical connections between the sensor and the monitoring electronics facilitates aseptic operation, and makes the sensor platform ideally suited for monitoring bacteria from within, for example, sealed food containers.
本文介绍了一种使用无线磁弹性传感设备对铜绿假单胞菌（P. aeru）浓度进行实时定量的方法。该传感器通过在磁弹性带上涂覆聚氨酯保护膜制成。响应外部施加的随时间变化的磁场，磁弹性传感器以共振频率振动，该共振频率可通过监测传感器发出的磁通量远程确定。随着铜绿假单胞菌在生长繁殖过程中消耗培养基中的营养物质，共振频率会因液体培养基性质的变化以及细菌在传感器上的附着而改变。利用石英晶体微天平（QCM）、显微镜成像和电导率测量研究了性质（电导率、粘度、质量）的影响。使用所述技术，我们能够直接定量10³至10⁸个细胞/毫升的铜绿假单胞菌浓度，在约20 Hz的噪声水平下检测限为10³个细胞/毫升。传感器与监测电子设备之间不存在任何物理连接，便于进行无菌操作，使该传感器平台非常适合例如从密封食品容器内部监测细菌。
