Advances in Giant Magnetoresistance Biosensors With Magnetic Nanoparticle Tags: Review and Outlook

• Published in: IEEE transactions on magnetics Vol. 44; no. 7; pp. 1687 - 1702
• Main Authors: Wang, S.X., Guanxiong Li
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.07.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Biomolecule detection; Biosensors; Cardiac disease; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Giant magnetoresistance; GMR biosensor; magnetic biochip; magnetic nanoparticle; Magnetic sensors; Magnetism; Materials science; Nanobioscience; Nanoparticles; Other topics in materials science; Physics; Proteins; R&D; Research & development; Sensor arrays; Sensors; spin valve sensor; Spin valves; Temperature sensors; Nanoparticles; magnetic nanoparticle; spin valve sensor; GMR biosensor; Valves; Biomolecule detection; Magnetoresistance; magnetic biochip; Magnetic properties
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2008.920962

We present a review of giant magnetoresistance (GMR) spin valve sensors designed for detection of magnetic nanoparticles as biomolecular labels (nanotags) in magneto-nano biodetection technology. We discuss the intricacy of magneto-nano biosensor design and show that as few as approximately 14 monodisperse 16-nm superparamagnetic nanoparticles can be detected by submicron spin valve sensors at room temperature without resorting to lock-in (narrow band) detection. GMR biosensors and biochips have been successfully applied to the detection of biological events in the form of both protein and DNA assays with great speed, sensitivity, selectivity, and economy. The limit of molecular detection is well below 10 pM in concentration, and the protein or DNA assay time can be under two hours. The technology is highly scalable to deep multiplex detection of biomarkers in a complex disease, and amenable to integration of microfluidics and CMOS electronics for portable applications. On-chip CMOS circuitry makes a sensor density of 0.1-1 million sensors per square centimeter feasible and affordable. The theoretical and experimental results thus far suggest that magneto-nano biochip-based GMR sensor arrays and nanotags hold great promise in biomedicine, particularly for point-of-care molecular diagnostics of cancer, infectious diseases, radiation injury, cardiac diseases, and other diseases.