Black phosphorus quantum dots(BPQDs)are a kind of outstanding optical material due to the tunable band structure.However,their fluorescence property and stability are obviously weakened in the aqueous phase,which extr...Black phosphorus quantum dots(BPQDs)are a kind of outstanding optical material due to the tunable band structure.However,their fluorescence property and stability are obviously weakened in the aqueous phase,which extremely restricts the development of BPQDs.Here,we propose a new method to prepare stable BPQDs in an aqueous solution directly with high absolute fluorescence quantum yield.Aqueous phase BPQDs are synthesized by liquid exfoliation and hydrothermal with NH_(2)-polyethylene glycol(PEG)-NH_(2) as the modification agent to protect the BPQDs,which have high stability more than six months.In addition,NH_(2)-PEG-NH_(2) is also a surface passivation agent to enhance the emission of BPQDs by forming P-N bonds,which is confirmed by an absolute fluorescent quantum yield of 11.5%.Moreover,BPQDs show excellent resistance to a strong acid environment and high ionic strengths except for Fe^(3+).Therefore,the BPQDs are a kind of highly selective and linear response fluorescence probe for Fe^(3+).Considering the good biocompatibility of BPQDs,they are employed as cell fluorescent label probes and show excellent fluorescence imaging contrast.Based on the unique structural stability and fluorescence performance in the aqueous phase,BPQDs are potential candidates for Fe^(3+)detection and optical bio-imaging.展开更多
The accurate diagnosis of tumor at the early stage depends on efficient medical imaging methods using probes with high sensitivity to the environment of tumor cells.For this purpose,we design the Fe_(3)O_(4)-rhodamine...The accurate diagnosis of tumor at the early stage depends on efficient medical imaging methods using probes with high sensitivity to the environment of tumor cells.For this purpose,we design the Fe_(3)O_(4)-rhodamine 6 G(Rh6G)nanoparticles(NPs)as a kind of dual-mode probe for fluorescence and magnetic resonance imaging(MRI).The Fe_(3)O_(4)-Rh6G NPs are demonstrated to be Fe^(3+)enhanced and pH-sensitive fluorescent agents,and the strongest fluorescence performance occurs under the pH value of 3.Cyto-toxicity assessment in HeLa cells proves the good biocompatibility and low toxicity of the Fe_(3)O_(4)-Rh6G NPs.The consequent fluorescence experiments in tumor cells show good imaging contrast,which is con-tributed by both the Fe^(3+)released from Fe_(3)O_(4)and the acid environment of tumor cells.Moreover,the Fe_(3)O_(4)-Rh6G NPs are superparamagnetic and have a strong MRI T 2 contrast effect.According to the per-formance in fluorescence and MRI tests,the Fe_(3)O_(4)-Rh6G NPs are potential dual-mode probes for MRI contrast agents and fluorescence probes with high biocompatibility for early-stage tumor detection.展开更多
基金partially supported by the National Key Research and Development Program of China(No.2019YFB2005801)the National Natural Science Foundation of China(Nos.51671019,52061135205,51971024,51731003,51971023,51927802)the Beijing Natural Science Foundation Key Program(No.Z190007)。
文摘Black phosphorus quantum dots(BPQDs)are a kind of outstanding optical material due to the tunable band structure.However,their fluorescence property and stability are obviously weakened in the aqueous phase,which extremely restricts the development of BPQDs.Here,we propose a new method to prepare stable BPQDs in an aqueous solution directly with high absolute fluorescence quantum yield.Aqueous phase BPQDs are synthesized by liquid exfoliation and hydrothermal with NH_(2)-polyethylene glycol(PEG)-NH_(2) as the modification agent to protect the BPQDs,which have high stability more than six months.In addition,NH_(2)-PEG-NH_(2) is also a surface passivation agent to enhance the emission of BPQDs by forming P-N bonds,which is confirmed by an absolute fluorescent quantum yield of 11.5%.Moreover,BPQDs show excellent resistance to a strong acid environment and high ionic strengths except for Fe^(3+).Therefore,the BPQDs are a kind of highly selective and linear response fluorescence probe for Fe^(3+).Considering the good biocompatibility of BPQDs,they are employed as cell fluorescent label probes and show excellent fluorescence imaging contrast.Based on the unique structural stability and fluorescence performance in the aqueous phase,BPQDs are potential candidates for Fe^(3+)detection and optical bio-imaging.
基金the National Key Research and Development Program of China(Grant No.2022YFA1204000)the National Natural Science Foundation of China(Grant Nos.52061135205,51971024,51971023,51927802,and 51671019)the Beijing Natural Science Foundation Key Program(Grant No.Z190007).
文摘The accurate diagnosis of tumor at the early stage depends on efficient medical imaging methods using probes with high sensitivity to the environment of tumor cells.For this purpose,we design the Fe_(3)O_(4)-rhodamine 6 G(Rh6G)nanoparticles(NPs)as a kind of dual-mode probe for fluorescence and magnetic resonance imaging(MRI).The Fe_(3)O_(4)-Rh6G NPs are demonstrated to be Fe^(3+)enhanced and pH-sensitive fluorescent agents,and the strongest fluorescence performance occurs under the pH value of 3.Cyto-toxicity assessment in HeLa cells proves the good biocompatibility and low toxicity of the Fe_(3)O_(4)-Rh6G NPs.The consequent fluorescence experiments in tumor cells show good imaging contrast,which is con-tributed by both the Fe^(3+)released from Fe_(3)O_(4)and the acid environment of tumor cells.Moreover,the Fe_(3)O_(4)-Rh6G NPs are superparamagnetic and have a strong MRI T 2 contrast effect.According to the per-formance in fluorescence and MRI tests,the Fe_(3)O_(4)-Rh6G NPs are potential dual-mode probes for MRI contrast agents and fluorescence probes with high biocompatibility for early-stage tumor detection.
