Abstract: Systems and methods that enable the rapid identification of target molecules present in a sample at low concentrations is provided. The system includes a sample volume, and a detection structure that is connected to the sample volume by a conduit. The detection structure includes a microfluidic chip that defines a plurality of fluid channels. The walls of the fluid channels are formed from or covered with a metal oxide to which target molecules attach. After the sample volume has been passed through the detection structure, and in particular through the channels, visible microparticles are passed through the detection structure. The visible microparticles are configured to have an affinity for the target molecules. The microfluidic chip is then imaged to detect visible microparticles, and to thereby obtain information regarding the presence of the target molecules.