Most methods used in virus and bacterium detection are based on confirmation of reactions between unknown samples and known probes. Since several bacterium species can survive in one sample, these methods have to be used to perform detections one by one with different probes, Which are with low efficiency. An experiment using mixed probes to detect two blended proteins at the same time is designed. By monitoring the binding curves of these two probe-target reactions with an optical reflectivity difference method, it is explicit whether there are two different proteins in the sample. The demonstration experiments show potentials of this method for higher throughput detection of viruses or bacteria.