This paper presents a preliminary study of the impact of potential contrast enhancing agents on a 2-port microwave imaging system. To this end, we have conducted microwave measurements inside a dual cylindrical tank, comprised of an outer and inner cylinder filled with high and low loss liquids, respectively. A third smaller cylinder inside the low loss filled tank represents a target. The target materials consisted of safflower oil, water, PEGylated zinc oxide nanoparticles dispersed in water, and saline with varying concentrations of salt. To benchmark our experimental results, we have also performed accurate numerical simulations of the system under three target scenarios: safflower oil, water, and PEGylated zinc oxide suspension. Our results show that the difference in received signal strength in scenarios with and without PEGylated zinc oxide nanoparticles in our 2-port system was comparable to measurement error. However, with the use of varying concentrations of saline solutions as a target, we have observed a significant difference in received signal strength.