Nanotechnology, such as nanoelectronic biosensors, is bringing new opportunities and tools to the studies of cell biology, clinical applications, and drug discovery. In this study, cyrstalline silicon nanowire based field-effect transistors fabricated using top-down approach were employed to parallelly detect pro-inflammatory cytokines in the complex biological fluids (cell culture medium and blood samples) with high specificity and femtomolar sensitivity. Using this technique, the dynamic secretion of TNF-alpha and IL6 was revealed during the immune response of macrophages and rats to the stimulation of bacteria endotoxin. This technique could provide a unique platform to examine the profile of complex immune responses for fundamental studies and diagnosis. © 2010 Elsevier B.V.