Smartphone-based rapid quantitative detection of luteinizing hormone using gold immunochromatographic strip

Abstract Measurement of the luteinizing hormone (LH) level is very important in assisted reproduction, the diagnosis of ovarian diseases, and evaluation of clinical effects. The objective of the present study was the development of a smartphone-based quantitative method for determining the LH level using a gold immuno-chromatographic strip(GICS). In the developed method, a smartphone is used to obtain the image of the GICS and Canny operator and fuzzy c-means clustering algorithms are used to extract the test and control lines of the GICS. A luminance compensation method is used to reduce environmental interference and increase the detection consistency of the GICS image. Experimental results revealed that the proposed method effectively reduced the relative standard deviation (RSD) of the measurements, afforded high linearity within LH levels of 1.0–83.3 mIU/mL (r = 0.996), and was highly reproducible using different types of smartphones and GICSs. The proposed method was further used to detect clinical serum samples (n = 31), with the achievement of a corresponding correlation coefficient of 0.974 against conventional large biochemical instrument; and to track the urine LH level of a volunteer during ovulation, with quantitative results obtained within 15 min. The method was found to be highly efficient and sensitive and is thus potentially applicable to rapid quantitative LH testing.