In this study,a high sensitive nano fluidic device is designed and fabricated by incorporating silicon nanowires gated nano fluidic systems and nanoparticles-based redox signal amplification for single bacterial detection in whole blood sample.The possibility of single-bacterium detection is realized here by using electroactive molecules modified on Mesoporous Silica nanoparticles (MSNs).The detection limit of the electroactive molecule is near 1 fM,and the dynamic range is between 1fM to 10 pM by CV measurements when immobilized on MSNs.Porous Si-NPs give around 100 times binding surface area enhancement larger than solid Si-NPs can provide at the same size.The Porous Si-NPs give us over 2-3 order enhancement for Ox-Red signal.The results show that this biochip system has a great potential for single-bacterium detection.In this work,Nanoparticles labeled with antibody and electroactive molecules were used as transducers to amplify the signal by increasing the signal to noise ratio,and reducing the response time [2].Figure 1 shows the mechanism.On the other hand,a silicon nanowires nano-filter valve for molecule concentration is adopted here for bacteria concentration and separation [4] in the nanofluidic systems for blood sample pretreatment.We consolidate these two techniques for few to single bacterial detection in 1μl sample without further amplification.A schematic view of the chip design and the operation principle is shown in Figure 2(a).We used microfludic system to control the modified MSNs previously functionalized with electrochemically active molecules into the electrochemical detection areas.The bacteria bound MSNs will be further separated from free MSNs using an array of silicon nanowires filter (figure 2b,3a) and enter the detection array electrodes.The detection chamber was designed to equip antibody-based,electrochemical detection areas,each for one bacterial pathogen (fig.2c).Figure4 shows the nanofabrication of MSNs supporting from NHRI (nano biomedical group).The microfabrication processes of electrochemical immunosensor microfluidic chip was shown in figure 5.Figure 6(a) shows the oxidation and reduction signals of MSNs binding the electroactive molecules,3-Amino-1,2,4 thriazole-5-thiol,with different concentrations.It reveals a potential of this device for few to single bacteria detection in μl sample.