The development of new strategies and methodologies to directly, selectively, and sensitively record chemical signals of neurons involved in brain functions has drawn more and more attention because recording of the dynamic change of chemical signals affords a platform to understanding the chemical essence involved in various brain functions, for example, neurotransmission and the diagnosis and therapy of diseases. Electrochemical methods based on bioelectrochemical mechanisms are particularly attractive for probing brain chemistry with a high temporal and spatial resolution. This topic will focus on our attempts on enabling bioelectrochemistry for in vivo analysis, covering the fundamental aspects of bioelectrochemistry with direct electron transfer of laccase as example, recent updates in biofuel cells, and new electrochemical methods for in vivo analysis based on new biosensors and biogenerators. The biogenerators are envisaged to be one kind of novel neurochemical sensing technology, providing a new tool to understanding chemical essences underlying physiological and pathological processes. With the development of the interfacial bioelectrochemistry and energy conversion technologies, some kinds of new biogenerators will be developed to work efficiently in living systems.