Graham D L, Ferreira H A, Freitas P P, Cabral J M S
INESC Microsystems and Nanotechnologies, R Alves Redol 9, 1000 Lisbon, Portugal.
Biosens Bioelectron. 2003 Apr;18(4):483-8. doi: 10.1016/s0956-5663(02)00205-1.
Small magnetoresistive spin valve sensors (2 x 6 microm(2)) were used to detect the binding of single streptavidin functionalized 2 microm magnetic microspheres to a biotinylated sensor surface. The sensor signals, using 8 mA sense current, were in the order of 150-400 microV for a single microsphere depending on sensor sensitivity and the thickness of the passivation layer over the sensor surface. Sensor saturation signals were 1-2 mV representing an estimated 6-20 microspheres, with a noise level of approximately 10 microV. The detection of biomolecular recognition for the streptavidin-biotin model was shown using both single and differential sensor architectures. The signal data compares favourably with previously reported signals for high numbers of magnetic microspheres detected using larger multilayered giant magnetoresistance sensors. A wide range of applications is foreseen for this system in the development of biochips, high sensitivity biosensors and the detection of single molecules and single molecule interactions.
小型磁阻自旋阀传感器（2×6微米(2)）用于检测单个链霉亲和素功能化的2微米磁性微球与生物素化传感器表面的结合。使用8毫安感测电流时，取决于传感器灵敏度和传感器表面钝化层的厚度，单个微球的传感器信号在150 - 400微伏量级。传感器饱和信号为1 - 2毫伏，代表估计的6 - 20个微球，噪声水平约为10微伏。使用单传感器和差分传感器架构展示了链霉亲和素 - 生物素模型的生物分子识别检测。该信号数据与先前报道的使用较大的多层巨磁阻传感器检测大量磁性微球的信号相比具有优势。预计该系统在生物芯片、高灵敏度生物传感器以及单分子和单分子相互作用检测的开发中有广泛的应用。
