We review our recent progress in bringing fluorescent correlation spectroscopy (FCS) of single molecules on a silicon optofluidic platform. Starting from basic concepts and applications of FCS we move to a description of our integrated optofluidic device, briefly outlining the physics behind its function and relevant geometrical characteristics. We then derive an FCS theoretical model for our sensor geometry, which we subsequently apply to the examination of molecular properties of single fluorophores and bioparticles. The model allows us to extract the diffusion coefficient, translational velocity and local concentration of particles in question. We conclude with future directions of this research.