Novel NO Biosensor Based on the Surface Derivatization of GaAs by "Hinged" Iron porphyrins We thank Rachel Lazar for her help in the synthesis. This work was supported by the Israel Ministry of Sciences Tashtyoth program (D.C., R.N., and A.S.), and by a grant from the Fussfeld foundation (D.C. and A.S.). A.S. holds the Siegfried and Irma Ullman professorial chair.