title: Acoustic biosensors.
abstract: Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors.
authors.affiliation: Biotechnology Innovation Centre, Rhodes University, PO Box 94, Grahamstown 6140, South Africa.
authors.forename: Ronen
authors.initials: R
authors.lastname: Fogel
authors.affiliation: Biotechnology Innovation Centre, Rhodes University, PO Box 94, Grahamstown 6140, South Africa J.Limson@ru.ac.za.
authors.forename: Janice
authors.initials: J
authors.lastname: Limson
authors.affiliation: Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, U.K.
authors.forename: Ashwin A
authors.initials: AA
authors.lastname: Seshia
mesh_terms: D000162:Acoustics; D000669:Amplifiers, Electronic; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*
keywords: acoustic biosensors; bulk acoustic waves; microelectromechanical system (MEMS); piezoelectricity; quartz crystal microbalance; surface acoustic waves