Nanotechnology for single-cell bacterial activity monitoring

Bacterial infections are one of the main threats to human health, and the rapid, highly sensitive monitoring of bacteria is crucial for ensuring public health safety. However, most reviews have focused on discussing the progress of bacterial identification and sensing technologies, overlooking the significance of monitoring bacterial activity. In recent years, advanced nanotechnologies based on optical, electrochemical, and spatiotemporal resolved imaging have rapidly developed and been applied to the monitoring of bacterial activity at the single-cell resolution, providing powerful tools for high-resolution bacterial analysis. Here, the progress and application of advanced nanotechnologies for monitoring bacterial activity at the single-cell resolution are comprehensively reviewed. We comprehensively discuss the behaviors of single bacterial activity (including nanovibration, motion, bioelectricity, growth, and metabolism), coordination engineering strategies for improving the sensing performance of nanomaterials, and the latest developments in advanced nanotechnologies for monitoring various physiological activities of bacteria, introducing their principles, performance, and applicability. Finally, the challenges and prospects for the application of advanced nanotechnologies in single-cell bacterial activity monitoring are proposed to guide the design and development of novel single-cell bacterial monitoring platforms.