Multifunctional Hybrid Silica Particles for Multicolor Imaging and Multiplex Tasking

Abstract

Multifunctional submicron particles have recently emerged as great promises for biological applications such as bio-labeling, medical diagnostics, and drug delivery. These particles are non-toxic and have size comparable to biomolecules, becoming very suitable for biomedical applications. The particle structures can be engineered to perform multicolor imaging, as well as multiplex tasking such as site-selective binding, detection, and separation. In addition, these particles can load a large amount of fluorescent dye for signal amplification. Several synthetic techniques have been developed for a variety of submicron particles, including core-shell synthesis, layer-by-layer techniques, multi-block polymer emulsifications, and surface modifications. Silica particles are one of the most extensively studied particles as they can be easily modified with organic functionalities. However, these silica particles usually have only a single type of functional group. Therefore, multiple sequential modification steps have to be employed in order to attach multitasking components such as imaging components, drugs and targeting moieties. For wider biological applications, the development of a simple and efficient preparation method for particles with various types of functionalities is of great importance. Herein, a "ONE-POT"; synthesis of multifunctional hybrid silica (MHS) particles of uniform size and morphology with homogeneously distributed multiple functional moieties is reported. The MHS particles can be tagged with various multitasking components for detection, selective binding, and separation using different functionalities, in an easier and more flexible way than those particles with a single functional group. Moreover, each functional moiety can be further modified with additional organic or inorganic groups. We demonstrate here following abilities of MHS particles: 1) expansion of surface functionality through the reaction with organic or inorganic compounds; 2) multicolor imaging by surface-conjugation with multiple dyes; 3) controlled assembly of 3-dimensional aggregates from two different types of MHS particles; 4) multiplex tasking through dye-tagging and selective binding to a patterned surface.