1. Electrical Engineering Department, University of California, Los Angeles, Los Angeles, CA 90095, USA.
2. Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
3. California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA.
4. Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
5. Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.