We　report　a　rational　strategy　for　scalable　production　of　highly　fluorescent　CQDs　in　high　yields　(50-92%)　based　on　controlled　molecule　fusion　of　activated　polycyclic　aromatic　hydrocarbon　in　environmentally　friendly　polar　solvents.　By　simply　varying　the　composition　of　reaction　solvents,　their　bandgaps　were　systematically　manipulated,　enabling　the　adjustment　of　fluorescent　emissions　from　blue　to　red.　Similar　to　conventional　organic-soluble　quantum　dots　but　distinct　from　extensively　reported　water-soluble　CQDs,　the　CQDs　engineered　in　polar　solvents　are　highly　soluble　in　organic　solvents　and　possess　main　features　of　intrinsic　bandgap　transitions,　including　overlapping　of　absorption　and　excitation　spectra,　excitation-independence　fluorescence,　the　inversely　proportional　relationship　of　the　bandgaps　with　fluorescence　peak　wavelength,　and　mono-exponential　fluorescence　decay.　What＇s　more,　the　red-fluorescent　CQDs　were　encapsulated　by　liposomes,　providing　good　biocompatibility　and　excellent　in　vitro　and　in　vivo　imaging　capabilities.　(C)　2017　Elsevier　Ltd.　All　rights　reserved.