Using the Taguchi method to optimize the inspection equipment for human chorionic gonadotropin detection

This study successfully fabricated the optical inspection system for detecting the commercial human chorionic gonadotropin (hCG) strips (cut-off value of the hCG commercial product is 25 mIU/mL) and developed the detection model from qualitative to quantitative analysis. In order to achieve the better linearity and decrease the standard deviation (increase the signal to noise ratio, S/N), the Taguchi method was used to find the optimal parameters in the optical inspection system. The hCG strip was based on the lateral flow immunoassay, and the color of the test and control line was caused by the colloid-gold. Because of the sandwich model, the color of the colloid-gold in the test line was darkened by increased the hCG concentration. In the results, the S/N was increased from 43.48 to 53.38 dB, and the hCG concentration detection was from 6.25 to 50 mIU/mL (the standard deviation less than 10%). The optical inspection system had the optimal parameters to decrease the detection limit and increase the linearity by using the Taguchi method and could apply to detect various commercial products (e.g. KET, Troponin I, FABP, etc.).