An integrated system of RBCs sorting and Brownian motion bio-sensing technique

Abstract

A clinical sorting chip integrated with new protein sensing technique has been developed in this work. Antibodycoated nanobeads reacted with antigen was separated from blood plasma based on dielectrophoresis (DEP) forces. MEMS fabrication process was used to produce the bio-chip and only two photo masks were required in the experiment. By using oxygen-plasma direct bonding method, the assembly of an electrode chip and the microchannels will form a set of RBCs and nanobeads separating chip. The original concentration of antigen can be rapidly estimated by nanobeads' Brownian motion measurement in varies of the viscous solutions. During the antibody-antigen reacting, the mean value of the beads diameter increased so that the Brownian velocity decreased with increasing time. The Brownian motion of nanobeads was observed and measured by micro-particle tracking velocimetry (P P-PTV).