摘要
A new type of self-targeting carbon dot （CD-Fla） for the detection of the toxic heavy metal ion Pb^2＋ was synthesized via a one-pot hydrothermal route using flavonoid extracts of Ginkgo biloba leaves as the starting material. As-prepared CD-Fla exhibited excellent biocompatibility and strong blue emission with a quantum yield of 16.1% and significant fluorescence quenching selectivity for Pb^2＋ without using any additional targeting molecules. CD-Fla could detect Pb^2＋ quantitatively within the range 0.1-20.0 nM, with an ultrahigh sensitivity of 55 pM. The selectivity of CD-FIa for Pb^2＋ was nearly one order of magnitude higher than that for other relevant metal ions. This was much better than ever reported CD-based metal ion sensors. The high sensitivity and selectivity were due to the incorporation of certain flavonoid-like moieties into CD-Fla. CD-Fla was also demonstrated to be a good probe for fluorescence tracing of intracellular Pb^2＋. The capability of CD-Fla was further improved when it was doped on agarose hydrogel. CD-Fla-doped agarose hydrogel （CD-AHG） allowed for visual fluorescence detection and removal of Pb^2＋ from water. This was confirmed by testing CD-AHG in actual water samples taken from the Jialing River （Chongqing, China）. The Pb^2＋ adsorbed CD-AHG was regenerable in HC1 solution. This study will open a new avenue for synthesizing intelligent materials capable of simultaneously targeting, detecting, and treating heavy metal ions.
A new type of self-targeting carbon dot （CD-Fla） for the detection of the toxic heavy metal ion Pb^2＋ was synthesized via a one-pot hydrothermal route using flavonoid extracts of Ginkgo biloba leaves as the starting material. As-prepared CD-Fla exhibited excellent biocompatibility and strong blue emission with a quantum yield of 16.1% and significant fluorescence quenching selectivity for Pb^2＋ without using any additional targeting molecules. CD-Fla could detect Pb^2＋ quantitatively within the range 0.1-20.0 nM, with an ultrahigh sensitivity of 55 pM. The selectivity of CD-FIa for Pb^2＋ was nearly one order of magnitude higher than that for other relevant metal ions. This was much better than ever reported CD-based metal ion sensors. The high sensitivity and selectivity were due to the incorporation of certain flavonoid-like moieties into CD-Fla. CD-Fla was also demonstrated to be a good probe for fluorescence tracing of intracellular Pb^2＋. The capability of CD-Fla was further improved when it was doped on agarose hydrogel. CD-Fla-doped agarose hydrogel （CD-AHG） allowed for visual fluorescence detection and removal of Pb^2＋ from water. This was confirmed by testing CD-AHG in actual water samples taken from the Jialing River （Chongqing, China）. The Pb^2＋ adsorbed CD-AHG was regenerable in HC1 solution. This study will open a new avenue for synthesizing intelligent materials capable of simultaneously targeting, detecting, and treating heavy metal ions.
基金
Financial support was provided by the National Natural Science Foundation of China （No. 21675016）, Chongqing Basic and Frontier Research Program （No. cstc2016jcyjA0328）, and the 100 Young Plan by Chongqing University （No. 0236011104410）.
