Multiple surface plasmon resonance quantification of dextromethorphan using a molecularly imprinted β-cyclodextrin polymer: A potential probe for drug–drug interactions

A surface plasmon resonance sensor for the detection of the common cough suppressant, dextromethorphan is demonstrated. Dextromethorphan is a pharmacological important marker drug used to identify the activity of the CYP2D6 class of p450 monoxygenases. Detection and quantification is achieved by measuring the refractive index changes of multiple surface plasmons resulting from the binding to template pockets within the thin layer imprinted β-cyclodextrin polymer. Initial investigations of the molecular imprinted polymer were conducted using reflectance spectroscopy. A detection limit of 0.035 μM and a dynamic range of 0.035 μM to 6.00 mM dependent upon instrumental setup have been demonstrated and the data are comparable with liquid chromatography-mass spectroscopy and commercial fluorescence based methodologies. The sensor could potentially be used to measure the consumption of dextromethorphan by CYP enzymes.