Embodiments of the present disclosure set forth a sensor for detecting a target of interest. One example sensor may comprise an apparatus for binding the target of interest and a draining unit for draining fluid from the apparatus. The apparatus may comprise a substrate, a material disposed on the substrate, and a probe disposed on the material and configured to bind to the target of interest. The probe is configured on the material to scatter light emitted from a light source when the target of interest is bound to the probe.