Abstract: The extrordinary optical performance of microbubble-based optofliudic sensors is highly appreciated in the field of microfliudic detection． However, analyte transport onto the sensing surface is in want of detailed studies． Theoretical analysis and finite-element-method simulation is combined in this work, to study systematically microfluidic transport inside optofluidic sensors． Diffusion limited adsorption speed is found to be enhanced via tapered capillary and microbubbles, to further optimize those microfluidic sensors．