Abstract
Sepsis is a serious infection disease usually caused by bacteria and posing immune system to attack body's own organs and tissues. Sepsis can be frightening because it can lead to serious complications that affect the functions of kidneys, lungs, brain, and hearing, and can even cause death. Traditionally, analysis of infectious bacteria is still based on culture-based protocols, which need days to obtain result. In addition, it can not be detected when the patient is in the initial stage with only several hundreds of bacteria in 1c.c whole blood. In order to push the detection limit, we use Mesoporous Silica Nanoparticles (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. Mesoporous Silica Nanoparticles (MSNs) labeled with antibody were used as transducers to amplify the signal by increasing the signal to noise ratio, and reducing the response time. S. aureus containing samples have been tested by using anti- S. aureus magnetic beads(MBs-pSAb) as capture phase and sandwiching afterwards with MSNs modified antibodies(sSAb-MSNs)detected using Cyclic Voltammetry (CV).A detection limit of 10cells mL-1. And a linear range from 10 to 104 cells mL-1 of S. aureus was obtained. The results show that this biochip system has a great potential for single-bacterium detection.