A new length detection-micro fluidic device using an autocatalytic reaction

摘要

A new length detection-micro fluidic device was developed using a sodium sulfite/hydrogen peroxide autocatalytic reaction system as a model reaction,and sub-ppm levels of horse radish peroxidase were determined with this device.Sodium sulfite solution containing bromo thymol blue as an indicator and hydrogen peroxide solution were pumped into a T-shaped mixer with the help of a microliter syringe pump and then mixed.The blue solution had changed to yellow beyond the midpoint of the fine pathway (micro channel).Furthermore,when horse radish peroxidase (PO_x) was pumped,a part of the blue solution in the micro channel (blue band) was shortened.Therefore,it was possible to determine the PO_x concentration by via the length of the blue band.The relationship between the blue band length (y,mm) and the common logarithm of the PO_x concentration (x,M) gave a straight line in the concentration range of 0.05-1 ppm.The equation for the straight line was as follows:y = -3.78 log(x) + 16.4.The correlation coefficient was gamma = 0.995,the relative standard deviation was 5.7% (n = 10),and the detection limits of the PO_x concentration was 0.029 ppm.