Spintronic Biosensors

The idea behind a spintronic biochip or biosensor is to replace traditionally used fluorescent markers by magnetic labels. Instead of detecting biomolecular recognition using expensive optical or laser-based 

The targets (biomolecules to identify in a sample such as a DNA strand complementary to the immobilized DNA probe, or antigens complementary 

The increase of the sensor size comes with a decrease in sensor label sensitivity, that is, the sensor response for a single magnetic label is smaller. On the other hand, the sensor dynamic range is larger as the sensor is able to detect a larger number of particles. In order to be sensitive to single labels 106 the sensor size can be reduced to match the label size [121], but in this case the assay biological sensitivity is smaller. 

2000- 1500- 1 1 r Tapered current lines focus labels in sensor area - 1 1 1 1 1 1 M / Washing 

This sensor size may thus be better suited for biological assays where a yes-or-no answer is required or only a small degree of signal quantification is needed. A potential application is the detection of mutations in DNA that occur in one or few nucleotides only, the so called SNPs (Single Nucleotide Polymorphisms). In this case it is then necessary to distinguish accurately between almost identical DNA strands and it only matters if the particular mutation being probed is present or not. 

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