Academic Appointments

Honors & Awards

  • Guggenheim Fellow, John Simon Guggenheim Foundation (1969, 1970 and 1978)
  • Christenson Fellow, Christenson Foundation (1986)
  • Distinguished Lecturer, Lee Magnetics Society (2002)

Professional Education

  • PhD, Columbia University (1954)

All Publications

  • Multiplex protein assays based on real-time magnetic nanotag sensing PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Osterfeld, S. J., Yu, H., Gaster, R. S., Caramuta, S., Xu, L., Han, S., Hall, D. A., Wilson, R. J., Sun, S., White, R. L., Davis, R. W., Pourmand, N., Wang, S. X. 2008; 105 (52): 20637-20640


    Magnetic nanotags (MNTs) are a promising alternative to fluorescent labels in biomolecular detection assays, because minute quantities of MNTs can be detected with inexpensive giant magnetoresistive (GMR) sensors, such as spin valve (SV) sensors. However, translating this promise into easy to use and multilplexed protein assays, which are highly sought after in molecular diagnostics such as cancer diagnosis and treatment monitoring, has been challenging. Here, we demonstrate multiplex protein detection of potential cancer markers at subpicomolar concentration levels and with a dynamic range of more than four decades. With the addition of nanotag amplification, the analytic sensitivity extends into the low fM concentration range. The multianalyte ability, sensitivity, scalability, and ease of use of the MNT-based protein assay technology make it a strong contender for versatile and portable molecular diagnostics in both research and clinical settings.

    View details for DOI 10.1073/pnas.0810822105

    View details for Web of Science ID 000262092800015

    View details for PubMedID 19074273

    View details for PubMedCentralID PMC2602607

  • Giant magnetoresistive biochip for DNA detection and HPV genotyping BIOSENSORS & BIOELECTRONICS Xu, L., Yu, H., Akhras, M. S., Han, S., Osterfeld, S., White, R. L., Pourmand, N., Wang, S. X. 2008; 24 (1): 99-103


    A giant magnetoresistive (GMR) biochip based on spin valve sensor array and magnetic nanoparticle labels was developed for inexpensive, sensitive and reliable DNA detection. The DNA targets detected in this experiment were PCR products amplified from Human Papillomavirus (HPV) plasmids. The concentrations of the target DNA after PCR were around 10 nM in most cases, but concentrations of 10 pM were also detectable, which is demonstrated by experiments with synthetic DNA samples. A mild but highly specific surface chemistry was used for probe oligonucleotide immobilization. Double modulation technique was used for signal detection in order to reduce the 1/f noise in the sensor. Twelve assays were performed with an accuracy of approximately 90%. Magnetic signals were consistent with particle coverage data measured with Scanning Electron Microscopy (SEM). More recent research on microfluidics showed the potential of reducing the assay time below one hour. This is the first demonstration of magnetic DNA detection using plasmid-derived samples. This study provides a direct proof that GMR sensors can be used for biomedical applications.

    View details for DOI 10.1016/j.bios.2008.03.030

    View details for Web of Science ID 000259425300015

    View details for PubMedID 18457945

    View details for PubMedCentralID PMC2573902

  • DOMAIN-WALL MOBILITIES IN YFEO3 JOURNAL OF APPLIED PHYSICS Tsang, C. H., White, R. L., White, R. M. 1978; 49 (3): 1838-1840