Fluorescence-converging carbon nanodots-hybridized silica nanosphere

An efficient way to converge the fluorescence of carbon nanodots (C-dots) was reported. C-dots were heated with 1 mL of SOCl 2 in 5 mL of acetonitrile until all the C-dots solid powder dispersed in the solution. After removing the excess thionyl chloride and acetonitrile, the C-dots acyl chloride was obtained. The C-dots acyl chloride was redispersed in 2 mL of acetonitrile with 5?60 μL of (3-aminopropyl) triethoxysilane (APTES) under stirring. The mixture was stirred at room temperature for 3?5 min to obtain the C-dots-APTES. The CSNs were synthesized by using a modified StoÄber method, in which C-dots were encapsulated during the formation of CSNs. Briefly, one solution containing ammonia, water, and ethanol was poured into another solution containing tetraethyl Orthosilicate (TEOS), C-dots-APTES, and ethanol under stirring. Similar to C-dots, the CSNs also exhibited broad excitation and presented different fluorescence under blue and green light excitation. As a result, the cells incubated with WGA-conjugated CSNs displayed yellow fluorescence under blue light excitation and red fluorescence under green light excitation. In contrast, the cells incubated with CSNs have no obvious fluorescence observed. The results demonstrate that the CSNs have significant potential for biolabeling applications.