A method and apparatus of determining the analyte concentration of a test sample is described. The nanoparticles in the coating may be boron nitride nanoparticles. Also disclosed are methods of manufacturing such devices under conditions that substantially prevent preferential partitioning of any of said bioactive agents to a surface of the biocompatible matrix polymer and substantially prevent chemical modification of said bioactive agents. The analysis system determines a second image to facilitate analysis of the first image and evaluates OPC designs based upon comparisons of the first and second image.