Abstract
The present invention relates to methods of making a trapped chromogenic compound (including photochromic and thermochromic compounds) by causing an open form of the chromogenic compound and a compound comprising an electrophilic moiety to be covalently bonded. In a preferred embodiment, the trapped, open, chromogenic compound includes an ester moiety derived from ingredients including an oxygen atom of an open pyran moiety and an acyl functional compound. The present invention also relates to trapped, open, chromogenic compounds and methods of using them. Preferred methods of using such compounds include methods of detecting biological molecules and/or toxic chemicals.