Mixed Surface Chemistry: An Approach to Highly Luminescent Biocompatible Amphiphilic Silicon Nanocrystals

Amphiphilic nanoparticles (AP-NPs) are attractive for many far-reaching applications in diverse sectors. Amphiphilic silicon nanocrystals (AP-SiNCs) are particularly promising for luminescence-based bioimaging, biosensing, and drug delivery because of their size- and surface chemistry-dependent photoluminescence (PL), high PL quantum yield, long-term photostability, and robustness to bioconjugation. Numerous studies demonstrated the synthesis of high-quality SiNCs that are compatible with organic solvents. However, preparing water-soluble SiNCs while maintaining their attractive PL properties is very challenging, and to date, only one report of blue-emitting AP-SiNCs has appeared. This report outlines a straightforward one-step thermal hydrosilylation approach that affords AP-SiNCs soluble in aqueous media in high concentrations (i.e., 14.4 mg/mL silicon core-based), exhibit bright long-lived PL in the red/near-infrared spectral region, are biocompatible, and present bioconjugable surface groups.