Preparation of dual-responsive hybrid fluorescent nano probe based on graphene oxide and boronic acid/BODIPY-conjugated polymer for cell imaging

Here, we report a pH- and thereto-responsive fluorescent nanomaterial of functimialized reduced graphene oxide (rGO) with cross-linked polymer produced via catechol-boronate diol binding.mechanism. When conjugated with the hydrophobic dye boron dipyrromethane (Bopipy), this material can act as a dual-responsive nanoplatform for cells imaging. 2-Chloro-3',4'-dihydroxyacetophenone (CCDP)-quaternized-poly(dimethylaminoethyl methacrylate-co-N-isopropylacrylamide) [C-PDN] was cross-linked with BODIPY and 4-chlorophenyl boronic acid (BA)-quaternized-poly(ethylene glycol)-g-poly(dimethylaminoethyl methacrylate-cp-N-isopropylacrylamide) [BBPPDN]. The GO was then reduced by the catechol group hi the cross-linked polymer to synthesize rGO nanopartides, which able to stabilize the quenching mechanism. This nanoplatform exhibits intense fluorescence at acidic pH and low fluorescence at physiological pH. Confocal laser scanning microscopy (CLSM) images shows bright fluorescence at lysosomal pH and total quench at physiological pH. Therefore, we have successfplly developed a promising sensitive bio-imaging probe for identifying cancer cells. (C) 2016 Elsevier B.V. All rights reserved.