Fully Printed Low-Voltage Field-Effect Transistor Biosensor Array for One-Drop Detection of Shewanella Onedensis MR-1 Bacteria

Fast and simple bacterial detection using an in situ measurement technique is indispensable for medical diagnosis, public hygiene, and environmental monitoring. However, current bacterial detection techniques still require large measurement apparatus with complicated analysis. In this work, we propose the use of a full printing process for the fabrication of field-effect-transistor (FET) biosensors using pi-junction gold nanoparticle (AuNP) ink and semiconducting single-wall carbon nanotube (sc-SWCNT) ink, which show a low voltage (<1 V) and high field-effect mobility (70 cm2 V-1 s-1), allowing for highly efficient and accurate bacterial detection from a minimal size of the target analyte droplet. This method provides a fully printed sensing platform for the determination of Shewanella onedensis MR-1 bacteria with a linear range of 10-1000 CFU in one drop of bacterial suspension (0.1 mu L) (i.e., 105 to 107 CFU/mL), which is promising for the practical application of low-cost and disposable biosensors, especially in the regions with restricted medical conditions.