Silk-chromophore composite materials for in situ oxygen sensing

A method of making an oxygen-sensing material, the method comprising:

• a) dissolving silk fibroin and a plurality of oxygen-sensing chromophores into an organic solvent;
• b) removing the organic solvent, thereby resulting in the oxygen-sensing material comprising the plurality of oxygen-sensing chromophores embedded in a solid matrix comprising the silk fibroin,
• wherein an amount of silk fibroin dissolved in step a) is selected to provide the solid matrix with silk fibroin in an amount by weight of at least 50% of a total weight of the solid matrix, wherein the removing is tailored to provide the following properties:
• the solid matrix is at least partially optically transparent to light at one or more wavelengths between 600 nm and 1300 nm;
• the solid matrix is biocompatible and biodegradable;
• the solid matrix is not a hydrogel;
• and
• and the plurality of oxygen-sensing chromophores are distributed throughout the solid matrix.

A method of using an oxygen-sensing material, the method comprising:

• acquiring phosphorescence data from an implantable oxygen sensor material,
• wherein the implantable oxygen sensor material comprises a plurality of oxygen-sensing chromophores embedded in and distributed throughout a solid matrix comprising silk fibroin in an amount by weight of at least 50% of a total weight of the solid matrix, wherein the solid matrix is at least partially optically transparent to light at one or more wavelengths between 600 nm and 1300 nm,
• wherein the solid matrix is biocompatible and biodegradable, and
• wherein the solid matrix is not a hydrogel.