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磁性粒子及檢測的介紹. T he real-life Magnetic Man Published on 11/16/2007. http://www.2spare.com/item_91569.aspx 如果是磁鐵人,磁場可能是如何產生 ?. Magnetic field sensors. H < 1 mT. H > 1 mT. Magnetometers. Gaussmeters. SQUID Flux gate M agnetoresistance. Hall effect Magnetoresistance Magnetodiode
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The real-life Magnetic ManPublished on 11/16/2007 http://www.2spare.com/item_91569.aspx 如果是磁鐵人,磁場可能是如何產生?
Magnetic field sensors H < 1 mT H > 1 mT Magnetometers Gaussmeters SQUID Flux gate Magnetoresistance Hall effect Magnetoresistance Magnetodiode Magnetotransistor
磁性儀器量測範圍 10-12 10-9 10-6 10-15 T magnetoresistance Flux gate (300 K) HTS SQUID LTS SQUID Brain Earth field Heart Magnetic immunoassay
Fig. 1. SQUID magnetometer principle Commercial SQUID magnetometer: the most sensitive available instrument for measuring in a research laboratory the magnetic moment of a sample. 商業化的SQUID量測儀器,其可提供加到到7 T的磁場,可量測磁滯曲線,磁性物質等等
Biosensor • Detector • Transducer • Sensitive biological sensor
動機 傳統免疫檢測Immunosorbent Assay(ELISA) 以測抗體而言 On-chip bio-probe (anti-gen) Serum with Adding indicators Fluorescence/Isotopes Test chip Wash/separation The amount of is probed by detecting the intensities of fluorescence/isotopes
Magnetic properties of clusters are measured to detect the amount of bio-target (antibody). • 磁標記方式 Magnetic particle Bio-probe Bio-target
Iron distribution in the liver of thalassemiaintermedia (A) and major (B) patients Origa, R. et al. Haematologica2007;92, 583-588
Transport of a magnetic marker through esophagus, stomach,and duodenum(十二指腸) in a frontal projection. The dots represent marker localizationsin time steps of 40 ms; altogether 40 minutes of the transport are displayed.
Magnetic properties of the magnetic clusters detected in MLI: • Magnetic Relaxation1,2(磁鬆弛免疫量測) • Mixed Frequency ac Magnetic Susceptibility3(混頻交流磁導率免疫量測) • Magnetic Remanence4(磁殘免疫量測) • Saturated Magnetization(飽和磁化) 1R. Kütitz et al., JMMM, 194, 62(1999) 2J. Clarke et al., APL, 81, 3094(2002) 3Y. Zhang et al., Deutsche Patentanmeldung 10309132.7(2003) 4K. Enpuku et al., JJAP, 38, L1102(1999)
Nano-Magnetic particles • Fabrication • Size • Stability • Drug delivery
磁性流體製程圖 Water Fe3O4 Dextran H.E. Horng et al., J. Magn. Magn. Mater., 283, 210 (2004)
葡聚醣披覆之Fe3O4磁珠 鏈球菌披覆之Fe3O4磁珠 生物探針披覆之Fe3O4磁珠
磁性粒子量測 • 磁減量檢測(ImmunoMagnetic Reduction, IMR) 在外加交流磁場頻率,當頻率在幾十到幾百萬赫茲時,磁性試劑中的單顆磁珠會受到外加交流磁場的驅動,產生旋轉,磁性試劑因而產生交流磁訊號(ac)。
樣品透過磁珠表面上的抗體,便可與磁性粒子相結合。如此,試劑中的部份磁珠粒子將會變大,造成數顆磁珠聚集在一起。樣品透過磁珠表面上的抗體,便可與磁性粒子相結合。如此,試劑中的部份磁珠粒子將會變大,造成數顆磁珠聚集在一起。 在此情況下,磁性試劑中可受外加磁場驅動而旋轉的磁珠數目,與先前未與待測樣品混合時的旋轉磁珠數目相較,會少了許多。 磁性試劑的交流磁訊號(ac)會因待測樣品中受檢生物分子與磁珠的結合,而被降低,此即我們稱此檢測方式為磁減量檢測的原因。並且,由上述中可知,當樣品中含有越多的待測生物分子時,將有越多的磁珠與待測生物分子相結合,因此將會表現出更大的磁減量。所以,透過磁性試劑的磁減量量測,我們可測得樣品中待測生物分子的含量