Incorporation of N and O into the shell of Silicon Nanoparticles offers tunable photoluminescence for imaging uses

摘要: Silicon nanoparticles (SiNPs) show tunable photoluminescence (PL), water-dispersibility, high photostability, and low cytotoxicity, thus constituting promising candidates for bioimaging applications. Because SiNP PL depends finely on particles’ crystallinity and surface composition, specific tuning of PL properties has remained elusive. Herein, using steady and time-resolved PL studies, absorbance spectroscopy, and electrochemical techniques, we have deeply analyzed the origin of the PL of SiNPs obtained from a wet chemical synthesis procedure based on the oxidation of Zintl salts in dimethyl formamide (DMF). Obtained SiNPs, surface-functionalized with propylamine terminal groups, were amorphous and 2.8–3.7 nm in size. The photophysical evidence, together with XPS and FTIR spectroscopy, supported a core–shell structure of the nanoparticles consisting of a silicon core surrounded by a 0.7–1.25 nm-thick …