Imprinted polymer-based enantioselective acoustic sensor using a quartz crystal microbalance

An enantioselective chemical sensor has been designed and fabricated. The s ensor is based on a molecularly imprinted polymer, serving as the recogniti on element, and a quartz crystal microbalance (QCM), used as the transducer . The polymer, imprinted with the chiral beta-blocking drug S-propranolol, was cast as a thin permeable film onto a gold electrode deposited on the qu artz crystal vibrator. The mass increase of the polymer due to analyte bind ing was quantified by piezoelectric microgravimetry with the QCM. The senso r was able to discriminate between the R- and S-propranolol enantiomers in acidified acetonitrile solutions owing to the enantioselectivity of the imp rinted sites. Detectability of S-propranolol was 50 mu mol dm(-3). The gene ral procedure developed here for preparation of the sensor can be adapted f or fabrication of a range of different stable analytical sensing devices fo r numerous analytes by using conventional molecular imprinting protocols.