A novel technique for the study of bioligand interactions based on combining flow injection on renewable surfaces with UV-visible absorptiometry is introduced. The concept is proven by monitoring the binding of various proteins to protein G and the binding of various insulin analogs to a monoclonal anti-insulin antibody, thus providing a comparison with the performance of surface plasmon resonance (SPR)-based techniques. The advantages of the bioligand interaction flow injection absorptiometry approach are speed, low cost, no need for regeneration of solid substrate, and spectral resolution not available with SPR sensing. It is believed that this technique will have an impact on the entire biosensor field since it allows simultaneous monitoring of labeled as well as nonlabeled species in real time over a wide spectral range with high sensitivity.