Novel Concepts of Photonic Crystals Based Hydrogels as Sensors in Medical Field and Research Applications

Functionalization and designing of photonic crystal hydrogels have been explained explicitly by using the relevant mathematical equations based on the Flory–Rehner equation for hydrogel swelling and the Bragg–Snell equation for diffraction. The design considerations for the photonic crystal hydrogels have been outlined. Applications of photonic crystals in medicine and biosensors have been reviewed and technically analyzed in this paper. Hydrogels of different types for photonic crystal biosensors have been described and discussed. Topics of tear glucose monitoring, mechanical force naked eye sensing, and creatinine-imprinted photonic crystal hydrogel sensors have been discussed. Some of the important recent breakthroughs in this field have been technically presented. The paper should be really useful for the experimentalists in medical and research works.