A prompt medical diagnosis is of major importance, starting the appropriate treatment earlier results in better outcomes and faster recovery times. Plasmonic biosensors based on photonic integrated circuits (PIC) are potential candidates in the development of lab-on-chip (LOC) technology, allowing digitalization of results and virtualization of laboratorial procedures in the detection of important biomarkers. These sensors have the advantages of high sensitivity and faster analysis when compared with traditional laboratorial methodologies. We study the possibility of exciting a surface plasmon, using low-cost fabrication methods and techniques based on amorphous silicon compounds, rib waveguide geometry and dimensions compatible with plasma-enhanced chemical vapor deposition (PECVD) and ultraviolet (UV) lithography. Results of Finite-Difference Time-Domain (FDTD) simulation of the plasmon excitation and sensor response are presented and discussed.