Colloidal Photonic Crystal Sensors

Photonic crystals (PhCs) have attracted intense research interest for sensing applications. PhC sensors utilize colloidal photonic crystals (CPCs) as transduction schemes owing to their simplicity, low cost, versatility, high signal-to-noise ratio, and ease of operation. The CPC sensors are usually implemented with responsive materials or functionalized with recognition elements or created with defects within the CPCs for the detection of target analytes. In general, external stimuli cause the changes in the effective refractive index or interparticle spacing of the CPC sensors, leading to Bragg diffraction shift of CPCs, which can be used as readout. Significant progress has been achieved in the development of a variety of CPC sensors, such as physical sensors, chemical sensors, and biosensors. In this book chapter, we summarize the progress made in this field and shed our light on the future development of high-performance CPC sensors.