Micropattern-enhanced Hydrophobicity of Centrifugal Fluid Valve in Immunosensor

Abstract

The purpose is to clarify the efficiency of a micro-periodic structure applied to fluid control mechanism to improve the hydrophobicity. The centrifugal microfluidic platform has a flow channel connecting two same-sized reservoirs. The micro-periodic structure was impressed on the flow channel of the centrifugal fluid valve integrated in the chip. Cortisol sample and ALP-labelled antibody conjugate solution were dropped simultaneously into the injection reservoir. Next, a chemiluminescent substrate was dropped into the reservoir. The substrate was hydrolysed by the ALP and the resultant intensity was measured using an optical reader. The relationship between the intensity, I, and the cortisol concentration, Cort, was given by I = 10×10^5 e^-0.032Cort (count/gate). On the other hand, the relationship without the micro-periodic structure was given by I = 8.5×10^5 e^-0.017Cort (count/gate). The sensitivity of the cortisol immunosensor was improved by adding the micro-periodic structure on the flow channel.