Colloidal Photonic Crystals for Biomedical Applications

Abstract

Colloidal photonic crystals (PCs) have attracted extensive interests because of their excellent optical properties and advantages such as ease in preparation, cost‐effectiveness, and versatility in functionalizations. After decades of development, numerous types of colloidal PCs are developed and found various applications in the field of biomedicine, including biosensors, microcarriers, drug delivery, cell research, and organs‐on‐chips, among others. Herein, the basic concepts and recent progress concerning the applications of the colloidal PCs in the biomedical field are provided. Initially, a brief introduction of the design and fabrication of colloidal PCs that are widely used in biomedicine is presented. Subsequently, the utilities of the colloidal PCs and their representative works in each application area are discussed in detail. Finally, a summary of challenges and perspectives is presented.

Electroconductive and Anisotropic Structural Color Hydrogels for Visual Heart‐on‐a‐Chip Construction

“…[15][16][17][18] Taking advantage of the features of these colorful hydrogels, the cardiomyocytes could be aligned and their beating would be reflected on the substrates bending or drawing, both of which could selfreport an obvious periodic color variation of the materials for the microphysiological visuality in the heart-on-a-chip. [19][20][21] Although with many progresses, the current construction of the patterned structural color materials-based heart-on-a-chip consists of several steps, including assembling, replicating, and chemical etching. Such necessary steps result in complexity in the manufacture, and residual etching liquid may leave biocompatible issues.…”

Aggregation‐induced emission: Red and near‐infrared organic light‐emitting diodes

“…Over the last few decades, great progress has been made in achieving highly efficient OLED devices, resulting in the commercialization of television, smartphone, and wearable devices 12–16 . Wherein, red light is not only an indispensable part of three primary colors for full‐color displays and white OLED but also widely applied in the field of optical telecommunication, information secured devices, night‐vision displays, and bioimaging 17–24 . Although there are rapid advances in organic light‐emitting materials with various colors through rational molecular design, 25–40 the development of red and near‐infrared (NIR) materials is much slower due to the intrinsic narrow bandgap and aggregation‐caused quenching (ACQ) effect 41–43 …”

Responsive Janus Structural Color Hydrogel Micromotors for Label-Free Multiplex Assays

“…Additionally, inverse opals can be modified with probes or functional sites, by which they can respond to the analytes and show the color change [28][29][30][31]. Therefore, the structural colors of the inverse opals can be used for sensing without further label strategies [32][33][34]. In contrast, graphene and its derivates are classic two-dimensional (2D) materials with an enormous specific surface area; so, they can be employed as carriers to load nanoparticles (NPs) with unique properties [35][36][37][38][39][40].…”