Detection of C Reactive Protein Based on Measurement of Brownian Motion by Micro Particle Tracking Velocimetry

　 In this research, a new CRP sensing technique has been successfully developed by detecting Brownian motions of nano polymer beads. The anti-CRP is coated on the surface of the fluorescent nano-beads to conjugate the CRP in the buffer solution. The Brownian motion velocity becomes slower when the bead size increases during the reaction process. This sensing technique is very useful for the detection of some diseases or virus. In addition, low cost and easy operation enable this technique to be easily integrated in some microfludic devices. In order to obtain the characteristics of particle Brownain motion in the static liquid, a measurement by using micro-particle-tracking-velocimetry (μ-PTV) is employed in our work. The results showed that the diameter of the bead increased from 300nm to 400nm when the CRP was conjugated on the bead surface. The reaction process indicated that the decreasing rates of Brownian velocities depended on the CRP concentration. The Brownian velocities decreased rapidly for high concentration of CRP like 100g/ml.The lower Brownian velocity was obtained for higher CRP like 100g/ml. the