Modulated molecular recognition was achieved in a temperature-sensitive molecularly-imprinted polymer. Using PNIPA as the temperature-sensitive element, the adenine-imprinted polymer (i.e., MIP-S) was prepared and characterized. The MIP-S exhibited a temperature-responsive molecular recognition behavior because of the thermal phase-transition within the MIP-S network. Specifically, below the transition temperature (e.g., 20 degrees C), the MIP-S showed a highly specific recognition for the imprint species (adenine). However, the MIP-S did not show any significant resolution for the imprint species (adenine) and its analogue (1-methyladenine) above the transition temperature (e.g., 40 degrees C). Such temperature-regulated recognition is comparable to a switch-on and switch-off process, thereby making tunable molecular recognition feasible. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2352-2360, 2009