Silica-nanobead-based sensors for analytical and bioanalytical applications

Silica-nanobead-based sensing systems have been developed and employed in various analytical and bioanalytical applications due to their attractive features, such as ideal modifiable surface, effective combining capacity with other nanomaterials, and good biocompatibility. The typical construction of silica-nanobead-based sensors includes the preparation of silica nanobeads and is followed by surface-chemistry modifications. In this review, we first cover the synthesis methods of different kinds of silica nanobeads in detail. We discuss the critical functional strategies for silica-nanobead-based sensing systems. This article also reviews silica-nanobead-based sensing and biosensing technologies, and highlights recent advances of representative examples with different sensing concepts. Finally, we conclude with a perspective on the opportunities and the challenges facing silica-nanobead-based sensors for further developments in this research field.