Exploring electrochemistry of carbon nanodots and its application in noninvasive bacterial growth monitoring.

Cost effective and miniaturized methods aiming for high throughput monitoring of bacterial growth are of great significance, especially for tracking disease progression in early stage as well as in screening antibiotic resistant species. Here, we demonstrate an electrochemical platform for noninvasive monitoring of bacterial growth by encapsulating bacterial cells and carbon nanodots in alginate microspheres. The synthesized carbon nanodots have been explored for electrochemical properties, and its redox properties have been utilized for developing bacterial growth monitoring platform. These synthesized CDs are sensitive to pH change and respond as change in redox potential over time as pH of the medium changes due to growth and metabolic activities of bacteria. We determined the bacterial growth kinetics by measuring the redox potential changes of the carbon nanodots over time. The developed platform has been demonstrated to detect the presence of bacteria, the difference in growth rates of bacteria and its susceptibility to the antibiotic with low bacterial counts (10 CFU) in 20 min; thus, redox properties of CDs has the potential to provide a sensitive detection platform.