Solid-bound, proton-driven, fluorescent 'off-on-off' switches based on PET (photoinduced electron transfer)

Anthracene-based, H(+)-driven, 'off-on-off' fluorescent PET (photoinduced electron transfer) switches. are immobilized on organic and inorganic polymeric solids in the form of Tentagel(R) and silica, respectively. The environment of the organic bead displaces apparent switching thresholds towards lower pH Values whereas the Si-O(-) groups of silica electrostatically cause the opposite effect. These switches are ternary logic gate tags, one of which can be particularly useful in Strengthening molecular computational identification (MCID) of small solid objects. (C) 2008 Elsevier Ltd. All rights reserved.