AUTOMATED COLORIMETRIC IMMUNOASSAY MICROSYSTEM FOR CLINICAL DIAGNOSTICS

An automated colorimetric immunoassay microsystem has been developed for the application of clinical diagnostics. The system can perform sandwich immunoassay around 1 hour automatically. The system consists of a motorized syringe pump, a motorized valve, and a microfluidic chip. The detection method is based on colorimetric immunoassay, which utilizes gold nanoparticle indication and gold enhancement amplification. The immunoassay result can be represented by color intensity and observed by a regular camera or even the naked eye in the microfluidic chip. An example of the sandwich immunoassay has been demonstrated using this automated microsystem. The analyte concentration ranging from 0.5 to 160 ng/ml can be detected quantitatively, and the detection limit is 0.5 ng/ml. Since the detection method is simple, low cost, and can be miniaturized, the proposed system has the potential to be developed to clinical diagnostic equipment.