Biomedical Engineering Reference
In-Depth Information
While significant strides have been made toward developing a true POC testing
device using magnetic nanotechnology [
23
-
25
], systems designed prior to this work
have relied on an external power source and an external PDA (either a pocket PC or
a laptop) for signal processing, data logging, and display. In the work presented
in this chapter, a fully integrated and cost-effective unit incorporating a built-
in microprocessor and miniature electromagnet has been designed to perform all
of these tasks. The handheld biomarker detection platform utilizing magnetically
responsive biosensors and MNP tags has tremendous potential for POC diagnostics
and personalized medicine. Throughout the development of this technology, a
conscious effort was made to create a platform that is both cost-effective and power
efficient for portable applications. The handheld detection module consumes an
average of 3.7 W from a rechargeable battery and weighs only 0.34 kg (0.75 lbs).
Moreover, the sensitivity of this handheld device and its multiplex capability are
noteworthy. The protein detection limit of 50 fM and 8-plex protein detection
achieved by this device are on par with or exceed many of the current desktop
protein detection platforms.
With the presented magnetic nanotechnology, patients can receive accurate
molecular-based diagnosis on their own in a matter of minutes. Furthermore,
due to the versatility of the sensing platform, the potential applications are
vast, particularly in the realm of infectious diseases. By providing disposable
sticks pre-functionalized with different capture antibodies, this technology can be
deployed for detection of a range of infectious diseases that pose large-scale public
health risks, such as HIV, HCV, tuberculosis,
Salmonella typhi
, and toxigenic
E. coli
,
as well as swine (H1N1) flu and avian (H5N1) flu. In addition, screening for enteric
infections is of particular interest, as the device will enable public health officials to
inspect and immediately detect contamination on-site, to aid in safeguarding food
and water sources for populations worldwide. This technology has the potential to
reshape the practice of medicine by providing societies in both the developed and
developing world with a new medical infrastructure: one that gives individuals the
tools to literally take healthcare into their own hands.
Acknowledgements
This work was supported, in part, by the United States National
Cancer Institute (grants 1U54CA119367, 1U54CA143907, 1U54CA151459, 1U01CA152737,
5R33CA138330, and N44CM-2009-00011), the United States National Science Foundation (grant
ECCS-0801385-000), the United States Defense Advanced Research Projects Agency/Navy (grant
N00014-02-1-0807), a Gates Foundation Grand Challenge Exploration Award, and the National
Semiconductor Corporation. RSG acknowledges financial support from the Stanford Medical
School Medical Scientist Training Program and the National Science Foundation Graduate
Research Fellowship Program.
References
1. R. Kotitz, H. Matz, L. Trahms, H. Koch, W. Weitschies, T. Rheinlander, W. Semmler, and
T. Bunte, SQUID based remanence measurements for immunoassays,
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