<br>Admitted to Ph.D. Candidacy: 2007-2008

Research: Biosensor Arrays for “Lab on a Chip” Diagnostics

Magnetic biosensors are under active development and may soon rival established biological detection methods that currently use fluorescent labels. Giant magnetoresistive spin-valve (GMR SV) biosensors operate on a quantum mechanical effect, spin dependent scattering, to detect the presence of biomarkers labeled with magnetic nanotags (Fig. 1). As a result of changing from an optical label to a magnetic label, this has potential for much higher sensitivity than alternate methods currently used today. Furthermore, when compared to complex and expensive optical detection systems, the GMR SV directly transduces the magnetic flux into an electrical signal and makes a low-cost, highly portable device feasible (Fig. 2). Lastly, we are designing a high throughput, large scale platform to interface an array of several hundred biosensors (Fig. 3).<br>


Fig. 1 – a) Magnetic immunoassay with magnetic nanotags b)GMR SV structure.<br>


Fig. 2 – NanoLab portable biomarker detection platform. <br>


Fig. 3 – Die photo of 256 sensor interface and data acquisition system.

<br>Email: drewhall AT stanford DOT edu<br>

Homepage: http://www.stanford.edu/~drewhall<br>