A Papertronic Sensing System for Rapid Visual Screening of Bacterial Electrogenicity

In this work, we report a papertronic sensing system with the ability to achieve easy, rapid, and sensitive characterization of bacterial electrogenicity from a single drop of culture. Paper was used as a device substrate that inherently produces favorable conditions for easy, rapid, and sensitive and potentially high-throughput controlling of a microbial liquid sample. Through an innovative microscale device structure and a simple transistor amplifier circuit directly integrated into a single sheet of paper substrate, a powerful sensing array was constructed, resulting in the rapid and sensitive characterization of bacterial electrogenicity from a microliter sample volume. The microbial current generations were amplified by the transistor providing power to a 4-wide LED circuit board indicator bar for the direct visual readout with the naked eyes. Depending on bacterial electrogenicity, the LED intensity was changed. We validated the effectiveness of the sensor using two known bacterial electrogens (wild-type S. oneidensis and P. aeruginosa) and hypothesis-driven genetically modified P. aeruginosa mutant strains.