Abstract: A sensor for isolating, identifying, and quantifying one or more analytes in a sample is provided, the sensor having a metal substrate base and a polymer waveguide disposed on the metal substrate base, the polymer waveguide including an optical channel and a polymer disposed in the optical channel; wherein the polymer waveguide optically couples a first and a second fiber optic cable. Also provided herein are methods of using the sensor for isolating, identifying, and quantifying one or more analytes in a sample, the method including contacting the polymer waveguide with a sample, sequentially heating the sensor to a plurality of temperature thresholds, obtaining an optical output at each temperature threshold, and analyzing differences in sequentially-obtained optical outputs in order to identify and determine concentrations of individual analytes of interest in the sample.