磁性粒子及檢測的介紹

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http://www.2spare.com/item_91569.aspx如果是磁鐵人，磁場可能是如何產生 ?

The real-life Magnetic Man Published on 11/16/2007

Magnetic field sensors

Magnetometers Gaussmeters

SQUID Flux gateMagnetoresistance

Hall effect MagnetoresistanceMagnetodiodeMagnetotransistor

H > 1 mTH < 1 mT

10-15 10-12 10-9 10-6

T

LTS SQUID

HTS SQUID

Flux gate (300 K)

magnetoresistance

Earth field Brain

Heart

Magnetic immunoassay

磁性儀器量測範圍

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

傳統免疫檢測 Immunosorbent Assay (ELISA)

Serum with

Test chip

On-chip bio-probe (anti-gen) Adding

indicators

Fluorescence/Isotopes Wash/separation

The amount of is probed by detecting the intensities of fluorescence/isotopes

以測抗體而言

動機

磁標記方式

Magnetic particle

Bio-probe

Bio-target

Magnetic properties of clusters are measured to detect the amount of bio-target (antibody).

Origa, R. et al. Haematologica 2007;92, 583-588

Iron distribution in the liver of thalassemia intermedia (A) and major (B) patients

Transport of a magnetic marker through esophagus, stomach, and duodenum( 十二指腸 ) in a frontal projection. The dots represent marker localizations in 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

Fe3O4 Dextran

Water

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。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