Synthesis of Starch-Based Amphiphilic Fluorescent Nanoparticles and Their Application in Biological Imaging

Due to the extensive source, good biocompatibility and biodegradability, the starch of carbohydrates has been extensively investigated for application in biological field. Recently, the development of fluorescent organic nanoparticles (FONs) on the basis of aggregation induced emission (AIE) dyes has attracted great research interest. In this article, novel starch-based S-TPEV polymers with AIE property were successfully fabricated by atom transfer radical polymerization (ATRP) of TPEV dye into water-soluble starch for the first time, subsequently, their structure and properties were detailedly investigated by 1H NMR, TEM, UV-vis, FL and FTIR. The characterization results confirmed the successful synthesis of S-TPEV polymers, and the molar fraction of TPEV and C6H10O5 ring in the starch polymers could be respectively calculated as approximate 5.8% and 94.2%. In aqueous solution, the as-prepared S-TPEV polymers will tend to self-assemble into FONs with 100-200 nm diameters, and their fluorescence intensity increased with the increase of the concentration of water in the mixed solution of water and DMSO, indicative of the obvious AIE property. More importantly, owing to their high water dispersity, good fluorescence and excellent biocompatibility, the S-TPEV FONs can be uptaken by HepG2 cells and show promising application in biological imaging field.