Abstract Here, several ring resonator nanostructure for biosensors are proposed. To evaluate the results, finite difference time domain (FDTD) method is applied. Also, several main parameters including transmission spectrum is analyzed to obtain of sensitivity and figure of merit. As the technology goes on, using sensors and biosensors are more attracted by many researchers in various fields such as medicine. Biosensors are devices, in them biological elements and analytes have interacted and the reaction between them is measured then would be expressed as understandably in output. Biosensors have various components such as analyte, bioreceptor, transformer, electronics and display and are in different groups based on their mechanisms. Biosensors could be used to detect and diagnose bacteria, viruses, and early detect of breast cancer. Various methods such as X-ray mammography, ultrasound scan, DBT, ultrasonography of breast, and so on have been provided, but they have some disadvantages. In the biosensors field, various methods are introduced for early detection of breast cancer. In this study some researches and experienced have been investigated. پرونده مقاله