Acoustofluidic device for acoustic capture of Bacillus anthracis spore analogues at low concentrationa

• Published in: The Journal of the Acoustical Society of America 2021-06, Vol.149 (6), p.4228-4238
• Main Authors: Plazonic, Filip, Fisher, Adam, Carugo, Dario, Hill, Martyn, Glynne-Jones, Peter
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/10.0005278

A portable device for the rapid concentration of Bacillus subtilis var niger spores, also known as Bacillus globigii (BG), using a thin-reflector acoustofluidic configuration is described. BG spores form an important laboratory analog for the Bacillus anthracis spores, a serious health and bioterrorism risk. Existing systems for spore detection have limitations on detection time and detection that will benefit from the combination with this technology. Thin-reflector acoustofluidic devices can be cheaply and robustly manufactured and provide a more reliable acoustic force than previously explored quarter-wave resonator systems. The system uses the acoustic forces to drive spores carried in sample flows of 30 ml/h toward an antibody functionalized surface, which captures and immobilizes them. In this implementation, spores were fluorescently labeled and imaged. Detection at concentrations of 100 CFU/ml were demonstrated in an assay time of 10 min with 60% capture. We envisage future systems to incorporate more advanced detection of the concentrated spores, leading to rapid, sensitive detection in the presence of significant noise.