Partial support for this work by the NSF-CRUI grant (No: DBI-9978806), the NIH-SCORE grant (Grant No: GM08101), and the Center for Environmental Analysis at CSULA is gratefully acknowledged.   We also thank Darell Brehm (ICM Technologies) for his generous donation of the carbon-coated crystals and Ron Johnson (CSULA) for his help on the cell construction.