Two-Dimensional Atomically Thin Tin-Based Fluorescent Oxide Synthesized at Ambient Temperature and Its Biomedical Applications

Abstract

Synthesis of atomically thin tin oxide nanosheets using a nonhydrolytic sol–gel method at ambient temperature is reported in the present work. After 10 min of probe sonication and 7 days of incubation at ambient temperature, ultrathin tin oxide nanosheets (SnONS) from 2 nm to 5 μm were formed due to interaction between tin chloride and acetone. The most upsurging property of SnONS was the inherent yellow fluorescence (λex= 420 and λem= 540 nm) phenomenon rarely reported with respect to tin-based nanosheets. The relative quantum yield of SnONS was ∼16%. The origin of fluorescence in SnONS is speculated to originate from multiple transitions in oxygen states of Sn, as confirmed by X-ray photoelectron spectroscopy. For biological applications, SnONS was phase transferred from acetone to water without compromising the fluorescent properties of SnONS. Image cytometry (Nucleo-Counter NC-3000) and laser confocal microscopy were used for comprehending the cellular biocompatibility and internalization of nanoparti...