Micro/nano biosensors had rapidly progressed and enabled a verity of applications that were otherwise impossible/challenging with tradi-tional methods. The three key components in micro/nano biosensors consist of (1) the analyte preparation (living cells or biomarker mole-cules), (2) signal transduction (from bio-signal/event to more readable electronic/optical signal), and (3) signal readout (preferably by inte-grated instrumentation). A verity of work has been dedicated to each of these three areas. It is now evident that micro/nanotechnology is playing a significant role in the development of cell and molecule bio-sensors. The performance of biosensors was significantly enhanced by combining the micro/nanostructures, which present unique physical and chemical characteristics due to various effects at these scales. Over the decades, many studies have been carried out to employ micro-and nano-based biosensors at the cellular or molecular level. Common aims among these novel biosensors were to achieve the char-acteristics of high sensitivity, high specificity, low detection limit, rapid response time, and easy-to-use.