While pathogenic bacteria contribute to a large number of globally important diseases and infections, current clinical diagnosis is based on processes that last a few days, employing complex and expensive techniques. Therefore, innovative, simple, rapid and low-cost solutions to effectively reduce the burden of bacterial infections are urgently needed. Here we demonstrate a label-free sensor for fast bacterial detection based on metal–oxide–semiconductor field-effect transistors (MOSFETs). The electric charge of bacteria binding to the glycosylated gates of a MOSFET enables quantification in a straightforward manner. We show that the limit of quantitation is 1.9 × 105 CFU/ml with this simple device, which is more than 10,000-times lower than is possible with existing techniques such as matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-ToF) on the same modified surfaces. Moreover, the measurements are extremely fast and the sensor can be mass produced at trivial cost as a tool for initial screening of pathogens.
Formisano, N., Bhalla, N., Heeran, M., Reyes Martinez, J., Sarkar, A., Laabei, M., ... Estrela, P. (2016). Inexpensive and fast pathogenic bacteria screening using field-effect transistors. Biosensors and Bioelectronics, 85, 103-109. https://doi.org/10.1016/j.bios.2016.04.063