Label free photonic sensors have shown increasing promise in monitoring molecular interactions. However, a system with full integration of the optical sensors together with a low noise readout and signal processing system in a high volume SOI process remains an unmet need. In this report we build a solid theoretical and experimental background for using the commercial CMOS 45nm RFSOI platform as a label free sensing process. In order to prove the feasibility of a fully integrated electronic-photonic platform for biosensing applications, the sensitivity of the platform is first characterized in Lumerical. A system level analysis is then presented by examining different photonic architectures using a Ring Resonator (RR) as a sensor. This report also addresses the challenges faced in creating a robust protein immobilization chemistry in 45nm process and efficiently delivering testing solutions using microfluidic channel networks. Finally, the capabilities of this platform are evaluated using RR filter banks, which include a sensing ring exposed to the testing solution and reference rings covered by PDMS for common mode error cancellation. The bulk sensitivity of the platform is demonstrated with different Refractive Index (RI) oils, while functionalized surface sensing sensitivity is evaluated with varying streptavidin concentration solutions flowing through a microfluidic channel. The analysis and results provided by this report open the pathway to the first Lab-on-Chip system with nanophotonic sensing and advanced electronics on a single die.