Authors: A.C. Mak, S. Osterfeld, H. Yu, S. Wang, R.W. Davis, O.A. Jejelowo, N. Pourmand
Affilation: Stanford University, United States
Pages: 27 - 30
Keywords: GMR sensor, multiplex mycotoxin detection, magnetic, nanotag
Rapid, sensitive and multiplexed measurement is vital in molecular diagnostics such as cancer diagnosis and pathogens detection. While highly specific and sensitive, traditional immunochemical assays such as enzyme-linked immunosorbent assays (ELISAs) often require expensive read-out equipment and lack the capability of multiplex detection. By combining the superior specificity of immunoassays with the sensitivity and simplicity of magnetic detection, we have developed a novel multiplex magnetic nanotag-based detection platform for cancer biomarkers and mycotoxins at sub-picomolar concentration level. Magnetic biosensors use superparamagnetic nanoparticles as labels in the detection of biomolecules. Unlike fluorescent labels, magnetic nanotags (MNTs) can be detected with inexpensive giant magnetoresistive (GMR) sensors such as spin-valve sensors. In the presented system, 64 spin-valve sensors (90 x 90 um2 each) are arranged in an 8 x 8 array. Sample is added to the antibody-immobilized sensor array prior to the addition of the biotinylated detection antibody. The sensor response to the addition of streptavidin-linked MNTs is recorded in real time. Here we demonstrate the simultaneous detection of multiple mycotoxins (aflatoxins B1, zearalenone and HT-2) and show that a detection limit of 50 pg/mL can be achieved.