Figure 2.

Fabrication of (A) HULK-in-microsphere sensors and (B) PdBP nanostabilized sensors. Top: Two similar oxygen-sensitive metalloporphyrin phosphors, HULK and PdBP, were incorporated into the sensors using distinct strategies. Middle: Hulk phosphors were cast into alginate microspheres, which were laminated with alternating charged layers of polyelectrolytes to contain the phosphors while allowing oxygen to diffuse freely. The less polar PdBP phosphors were trapped into a nanoethylcellulose matrix and stabilized with surfactant, which entangled and stabilized the phosphors while also allowing free access to oxygen. Bottom: Both HULK microspheres and PdBP nanoethylcellulose could be easily mixed into any of our available hydrogel solutions and cross-linked into an insertable sensor. Empty microspheres were also incorporated into PdBP-nanoethylcellulose designs in order to increase light diffusion.