Nanomechanical bio-sensing for fast and reliable detection of viability and susceptibility of microorganisms

• Published in: Sensors and actuators. B, Chemical Chemical, 2021-12, Vol.348, p.130650, Article 130650
• Main Authors: Venturelli, Leonardo, Harrold, Zoe R., Murray, Alison E., Villalba, Maria I., Lundin, Eric M., Dietler, Giovanni, Kasas, Sandor, Foschia, Raphael
• Format: Article
• Language: English
• Subjects: Antibiotics; Atomic force microscopy; Biological activity; E coli; Metabolism; Microbalances; Microorganisms; Quartz crystals
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2021.130650

The metabolic activity of living organisms results in cellular motion on a nanometric scale that can be efficiently detected by micro- and nano- fabricated sensors. Quartz crystal microbalance and atomic force microscopy (AFM) inspired techniques have recently demonstrated their ability to successfully measure the nanometric motion of microorganisms. Monitoring these fluctuations while exposing the microorganisms to various compounds (e.g., metabolic inhibitors and drugs, fixatives, etc.) provides a rapid, label-free assessment of cellular activity and the live versus dead state of both prokaryotic and eukaryotic cells. To date, microbial activity-induced nanometric oscillations of AFM cantilevers have primarily been measured using commercially available AFMs. In this article we present a novel, user-friendly mechano-sensing device, termed a Nanomotion Detector (NMD), recently developed in our laboratories, that simplifies AFM systems. This NMD offers a streamlined design that is simple to align, is optimized for assays with live cells and liquid exchange, and can be operated in a Peltier-controlled incubator providing thermal control. Here, we successfully tested the ability of the NMD to discern differences between the live/dead nanometric motion of Escherichia coli and Staphlococcus aureus exposed to antibiotics and fixatives. This NMD is a dedicated cell activity detector that can advantageously replace commercially available AFMs for nanomotion detection applications including rapid antibiotic sensitivity testing. •The NMD is a reliable and robust system that enables sensitive measurements of microbial activity with less than 100 cells.•Antibiotic susceptibility testing using the NMD has an efficient turnaround time amplifying the ability to fight infection.•The NMD provides an agnostic assay to detect life in natural samples with applications to astrobiological sciences.