A biological detection system for detecting a liquid sample containing a plurality of target biological particles includes a capturing device including a cell structure, an inlet, an outlet, a monolithic chip, and a layer of binding agent. The monolithic chip includes a substrate and a plurality of discrete nano-sized structures which are displaced from each other and each of which extends uprightly from the substrate to terminate at a top end. The layer of binding agent is formed on the top end of each of the discrete nano-sized structures for capturing the target biological particles.