Method for analyzing bio-substance

Abstract

A bio-substance analysis method using a sensing substrate having a fluid channel is disclosed. The method includes mixing retroreflective particles with a detection solution containing a target bio-substance, wherein a first bio-recognition substance selectively reacting with the target bio-substance is modified on the retroreflective particles; placing the sensing substrate so that a bottom is located under a cover in a direction of gravity; injecting the detection solution containing therein the retroreflective particles into a fluid channel and maintaining the solution in the channel for a first time duration; turning the sensing substrate upside down so that the bottom is located above the cover in the direction of gravity and maintaining the sensing substrate in the turned state for a second time duration; irradiating light into the fluid channel through the bottom; and generating and analyzing an image based on light retroreflected from the retroreflective particles.