A high-speed vibration milling (HSVM) method was applied to synthesize water-dispersible silicon quantum dots (SiQDs). Highly reactive free radicals (HOOCCH2CH2˙) produced from an acyl peroxide under HSVM conditions reacted with hydrophobic Si chips to produce highly water-dispersible SiQDs, which were characterized in detail by spectroscopic and microscopic techniques. Further experiments showed that the SiQDs are photostable, biocompatible, and suitable for long-term fluorescent cellular imaging. Our results provide a new methodology for large-scale synthesis of water-dispersible SiQDs, which are promising for various optoelectronic and biological applications. RSC Advances, 2015 |