Locating circulating tumor cells (CTCs) is crucial as they yield prognosis information for ovarian cancer. Current methods used to diagnose ovarian cancer include documenting CA-125 concentrations and transvaginal ultrasounds. It is difficult to find and differentiate between CTCs and other cells already circulating through blood. This study will discuss the use of photoacoustic flowmetry (PAF) to locate CTCs that have been coated with CuS nanoparticles circulating through a designed flow system. The hypothesis is that the CuS nanoparticles will bind to the CTCs using folic acid due to the folic acid receptors on CTCs.