The construction of electrochemical chiral interfaces using hydroxypropyl chitosan

A simple chiral electrochemical sensor based on hydroxypropyl chitosan (HPCS) covalently bound to multi-walled carbon nanotubes (MWCNTs) was developed for the recognition of mandelic acid (MA) enantiomers. HPCS preferably combines with (S)-MA over (R)-MA, which was attributed to the favorable host-guest interactions between HPCS and the MA enantiomers. In addition, the recognition efficiency was significantly increased after hydroxypropyl groups were grafted onto chitosan (CS), which may be due to a stereo-hindrance effect. Moreover, the electrochemical recognition of amino acid enantiomers was investigated; the functional groups of the enantiomers play an important role in the enantioselective discrimination.