Imprinting chirality in inorganic nanomaterials for optoelectronic and bio-applications: strategies, challenges, and opportunities

Abstract

Chirality, ubiquitous in biological systems, is the property of the non-superimposable structures found in both macroscopic and nanoscopic objects. In the last ten years, the research on chiral inorganic nanomaterials has witnessed tremendous growth due to their shape, size, crystal facets-controlled unparalleled physical, chemical, optoelectronic, and bio-compatibility features. Due to the quantum confinement, the chiral nanomaterials exhibit high anisotropy factors and, therefore, there has been an upsurge in research activities around the chiroptical and (bio)recognition properties of optically active inorganic nanomaterials. Advancements in synthesis and characterization technologies have made it possible to prepare complex multi-functional materials. Inorganic nanoparticles are known to exhibit fascinating semiconducting or metallic behavior and when combined with chirality, their usability in various devices is enhanced drastically due to an additional degree of freedom over achiral systems. In this review, we discuss different chemical routes to transfer chirality from intrinsic chiral systems into achiral nanomaterials for optoelectronics and bio-applications, in the light of recent experimental findings. Despite the progress in the research field of nanomaterials, imprinting chirality, device fabrication, scalability, long-term stability, and reproducibility remain challenging tasks that need to be addressed. Since the synthesis and growth mechanisms of chiral inorganic systems can be found in literature, here, we shed light only on the complimentary metal-oxides semiconductors (CMOS), and bio-compatibility of either intrinsic or imprinted chiral nanomaterials and their potential applications in next-generation chiroptical devices. We also discuss feasible strategies to resolve existing issues related to the integration into devices and their operational aspects.