A MOLECULAR LOCK-AND-KEY APPROACH TO DETECTING SOLUTION-PHASE SELF-ASSEMBLY - A FLUORESCENCE AND ABSORPTION STUDY OF CARMINIC ACID IN AQUEOUS GLUCOSE SOLUTIONS

We introduce a novel approach to the study of complex ternary systems where a fluorescent chromophore contains a functionality that incorpor ates into precrystalline aggregates in concentrated solutions. We demo nstrate the feasibility of this approach by using carminic acid, a flu orescent molecule possessing a pendant glycosyl moiety, in aqueous glu cose solutions. We report the steady state absorption and emission res ponse of carminic acid as well as its picosecond dynamical response. T hese data, taken collectively, show that saturated glucose solutions e xhibit anomalous molecular scale organization and that the persistence time of this organization is significantly less than a nanosecond. Ou r results indicate that kinetic contributions to crystallization are e xpected to play an important, sometimes dominant, role in this technol ogically important process.