Biosensing device (BioDe) technology has rapidly evolved, driven by breakthroughs in materials science, nanotechnology, and data analytics. These innovations have led to the development of highly sensitive, selective, and portable biosensors. Miniaturization of biosensors has enables high-throughput screening and precise analyte detection, while advancements in electrochemical transduction mechanisms—such as piezoelectric and triboelectric nanogenerators—allow biochemical interactions to be converted into electrical signals, facilitating real-time healthcare monitoring and p aving the way for self-powered sensors. This chapter introduces the concepts of BioDe, tracing its progression across generations to modern sensor platforms. It outlines the key structural components of biosensing devices and their evolution over time. Furthermore, this chapter briefly discusses the ongoing integration of machine learning (ML) and artificial intelligence (AI) into BioDe, enabling robust data analysis, pattern recognition, and predictive capabilities, ultimately improving sensor specificity and sensitivity. This chapter concludes with an outlook on upcoming BioDe and its impact on precision medicine and diagnostics.