Nitrogen-doped graphene quantum dots( N-GQDs)exhibiting excitation-independent green fluorescence emission( 536 nm) was facilely synthesized. The as-prepared N-GQDs showed a highly selective fluorescence quenching res...Nitrogen-doped graphene quantum dots( N-GQDs)exhibiting excitation-independent green fluorescence emission( 536 nm) was facilely synthesized. The as-prepared N-GQDs showed a highly selective fluorescence quenching response toward Hg2 + with a linear range of 0. 1-30. 0 μmol/L and detection limit of50 nmol/L. Based on the high affinity of biothiols( such as cysteine)toward Hg2 +, the quenched fluorescence of N-GQDs could be recovered upon addition of biothiols,and thereby a new fluorescence turn-on probe for cysteine detection was further developed. The linear range and detection limit for cysteine were found to be 0. 1-12. 5 μmol/L and 46 nmol/L,respectively. The present fluorescent probe worked well in a physiological pure water medium,allowing a fluorescence imaging of cysteine in living cells.展开更多
基金Shanghai Municipal Natural Science Foundation,China(No.16ZR1401700)Innovation Experiment Project for University Student of Donghua University,China(No.hsxy10201708)
文摘Nitrogen-doped graphene quantum dots( N-GQDs)exhibiting excitation-independent green fluorescence emission( 536 nm) was facilely synthesized. The as-prepared N-GQDs showed a highly selective fluorescence quenching response toward Hg2 + with a linear range of 0. 1-30. 0 μmol/L and detection limit of50 nmol/L. Based on the high affinity of biothiols( such as cysteine)toward Hg2 +, the quenched fluorescence of N-GQDs could be recovered upon addition of biothiols,and thereby a new fluorescence turn-on probe for cysteine detection was further developed. The linear range and detection limit for cysteine were found to be 0. 1-12. 5 μmol/L and 46 nmol/L,respectively. The present fluorescent probe worked well in a physiological pure water medium,allowing a fluorescence imaging of cysteine in living cells.
