Porous nanomaterials for biosensing and related biological application in in vitro/vivo usability

Porous nanomaterials (PNMs) refer to materials that have a porous structure on the nanoscale, characterized by a network of interconnected pores or voids. These materials exhibit unique physical and chemical properties due to their nanoscale size and the presence of pores. With the continuous development in nanotechnology and materials science, significant advancements have been realized in the design and approaches for various applications. In this case, PNMs have attracted significant attention due to their excellent biocompatibility, high loading capacity, controllable designability, and advantages in optical imaging. Therefore, it is necessary to investigate the ongoing developments in porous structures, particularly their applications in biosensing and in vivo scenarios, to demonstrate the advancements and latest research trends in this field. In this review, we present the diverse applications of PNMs, including porous silicon structures with facile approaches and expandable physical or optical properties, resulting in an excellent bioimaging performance; as useful substrates with superior loading capacity and easy intracellularization for drug delivery; and their good biocompatibility, degradability, and flexibility, making them suitable for in vivo applications, which can be achieved through a self-assembly path. Furthermore, the constituents of PNMs are highlighted and the influence of different factors on their in vivo and in vitro (biocompatibility and cytotoxicity) characteristics demonstrated. All these characteristics are appropriate for in vivo applications, outlining the significant potential of PNMs for biological applications and biosensing. The results show that PNMs are viable alternatives in current research and clinical applications. In this review, each section discusses and summarizes representative examples and analyzes the use of PNMs in biomedicine. Finally, the future of PNMs in biomedicine is explored, which can help researchers in understanding their prospective development.