Surface acoustic wave biosensors: a review

• Published in: Analytical and bioanalytical chemistry 2008-07, Vol.391 (5), p.1509-1519
• Main Authors: Länge, Kerstin, Rapp, Bastian E, Rapp, Michael
• Format: Article
• Language: English
• Subjects: Acoustics - instrumentation; Analytical Chemistry; Antibodies - chemistry; Antibodies - metabolism; Biochemistry; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; biosensors; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Chip; Food Science; Interaction analysis; Laboratory Medicine; Lithium - chemistry; Microfluidics - instrumentation; Microfluidics - methods; Monitoring/Environmental Analysis; Quartz - chemistry; Reproducibility of Results; Review; Sensitivity and Specificity; Solutions - chemistry; Solvents - chemistry; Specimen Handling - methods; Surface acoustic wave; Surface Properties; Tantalum - chemistry
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-008-1911-5

This review presents an overview of 20 years of worldwide development in the field of biosensors based on special types of surface acoustic wave (SAW) devices that permit the highly sensitive detection of biorelevant molecules in liquid media (such as water or aqueous buffer solutions). 1987 saw the first approaches, which used either horizontally polarized shear waves (HPSW) in a delay line configuration on lithium tantalate (LiTaO₃) substrates or SAW resonator structures on quartz or LiTaO₃ with periodic mass gratings. The latter are termed “surface transverse waves” (STW), and they have comparatively low attenuation values when operated in liquids. Later Love wave devices were developed, which used a film resonance effect to significantly reduce attenuation. All of these sensor approaches were accompanied by the development of appropriate sensing films. First attempts used simple layers of adsorbed antibodies. Later approaches used various types of covalently bound layers, for example those utilizing intermediate hydrogel layers. Recent approaches involve SAW biosensor devices inserted into compact systems with integrated fluidics for sample handling. To achieve this, the SAW biosensors can be embedded into micromachined polymer housings. Combining these two features will extend the system to create versatile biosensor arrays for generic lab use or for diagnostic purposes. [graphic removed]