To understand important questions at the interface of chemistry, biology and medical research, the development of new tools and instrumentation is a key aspect. Electrochemistry with its ability to monitor redox processes, resulting from only a few thousand electron transfers, is an ideal tool to investigate cell functions on the molecular level. Its combination with bioanalytical, chemical and biological techniques gives rise to promising approaches to tackle phenomena, such as cancer development and multidrug resistance. This seminar talk will present the efficacy of electrochemistry for the analysis of biological systems, ranging from tissue and cancer cells to bacteria. Bioelectrochemical methods for the quantitative analysis of biological systems will be introduced, including specialized techniques, such as scanning electrochemical microscopy (SECM) and I am looking forward to presenting some of the ongoing research at the University of Oxford toward the development of biosensors for the detection of sexually transmitted diseases and other pathogens.