Bacterial biofilms have a significant financial and health impact in many fields. It remains a fundamental challenge to understand and detect the formation of microbial biofilms on surfaces to counteract corrosion and biofouling processes. Current technologies for monitoring bacterial biofilm processes suffer from their own limitations and are in some instances very costly or harsh on the sample's integrity. In this thesis, the development of a real-time, label-free radiofrequency sensor dedicated to the monitoring of bacteria and biofilm growth is presented. The high sensitivity of the method highlights the growth of a biofilm at the early state of formation. This method was compared to low frequency electrochemical methods. The change of the electrode-solution interface during P. aeruginosa biofilm growth was monitored by in-situ measurement of the open circuit potential and correlated with the results obtained by electrochemical impedance spectroscopy and cyclic voltammetry. One of the objectives of this thesis is also to explore the application of this new real-time, label-free radio frequency sensor. It provides a new support tool and was able to track bacteriophage predation on P. aeruginosa bacteria at 300 MHz. Several biological events were captured with the sensor but were not detected with the other two methods tested. This proposed method should therefore be considered as a promising tool for biofilm monitoring to complement existing techniques.