A highly sensitive refractive index based etched optical fiber sensor for detection of human sperm

Human sperm functionality is one of the important factors for continuing natural reproduction, but due to the variation in environmental factors, its infertility is increased. Such agitating characteristics need the use of so-phisticated computer-aided devices, whose precision is not up to the mark, especially for the samples with a low concentration of sperms. Therefore, for the first time, a gold-graphene oxide capped etched optical fiber sensor is presented in this paper for the refractive index (RI) based detection of human sperm samples. The sensor takes the advantage of evanescent waves, which are excreting from the etched region, to sense the analytes. In this work, the sensing analysis is done by considering two different sensor structures, such as core-gold-sperm and core-gold-graphene oxide-sperm. The wavelength compatibility of sensor structures is examined by performing the sensing at 520 nm and 633 nm wavelengths. For the sensing process, the sperm samples of ten different people are collected with their concentration and mobility, and their RIs are obtained by using the ATAGO re-fractometer. The results are evaluated in terms of transmission spectra, sensitivity, quality factor, and figure of merit (FOM). The obtained results demonstrate that the core-gold-graphene oxide-sperm sensor structure is very efficient at the wavelength of 633 nm with the sensitivity, quality factor, and FOM of 203.72 & DEG;/RIU, 27.055 ������������ ������-1 and 27.309, respectively.