A survey of the 2006-2009 quartz crystal microbalance biosensor literature.

Since the publication of the original review of piezoelectric acoustic sensors in this series there has been a consistent, gradual expansion in the number of published papers using 'quartz crystal microbalances' (QCM). Between 2001 and 2009, the number of QCM publications per annum has increased from 49 to 273, with a two-fold increase in papers per annum between 2004 and 2008. Within the field, comparing the time covered by the current to the previous review, there are trends towards increasing use of QCM in the study of protein adsorption to surfaces (93% increase), homeostasis (67% increase), protein-protein interactions (40% increase) and carbohydrates (43% increase). New commercial systems have been released that are driving the uptake of the technology for characterization of binding specificities, affinities, kinetics and conformational changes associated with a molecular recognition event. This paper highlights theoretical and practical aspects of the principles that underpin acoustic analysis, then reviews exemplary papers in key application areas involving small molecular weight ligands, carbohydrates, proteins, nucleic acids, viruses, bacteria, cells and membrane interfaces.