Highly efficient hydrolysis of phosphodiester by a copper(II)-chelated chitosan magnetic nanocarrier

Abstract A novel heterogeneous magnetic nanocatalyst was designed by conjugating copper(II) ions with chitosan-bound magnetic nanocarrier. Its hydrolytic activity for phosphodiesters was evaluated by investigating the hydrolysis of secondary ester bis-(nitrophenyl) phosphate (BNPP) in aqueous media. The maximum hydrolysis rate of BNPP was observed around the p K a of nanocatalyst which was found to be 12. The kinetic studies revealed that the binding affinity of BNPP to the copper(II)-chelated chitosan magnetic nanocarrier was low as compared to other catalyst systems. However, the rate constants ( k cat ) and maximum reaction rate ( V max ) were found to be higher with lower activation energy for the developed nanocatalyst. Moreover, the developed nanocatalyst was magnetically recoverable and also had good reusability.