Amino acid derivatized carbon dots with tunable selectivity as logic gates for fluorescent sensing of metal cations

作者：Cheng Hung Jen; Kao Chang Long; Chen Yan Fu; Huang Ping Chih; Hsu Ching Yun; Kuei Chun Hsiung

来源：Microchimica Acta, 2017, 184(9): 3179-3187.

DOI：10.1007/s00604-017-2336-7

• Carbon dots (CDs)
• Fluorescent probe
• Logic gates
• Fluorescent quenching
• Quantum yield
• Metal cations
• Transmission electron microscopy
• Raman spectroscopy
• X-ray photoelectron spectrometry
• Water samples

Carbon dots (CDs) modified with ethylene diamine (EDA) and the amino acids (AAs) Cys, His, Lys or Arg were synthesized, and their structures were confirmed by high resolution transmission electron microscopy, Raman spectrometry and X-ray photoelectron spectrometry. It is found that derivatization of the CDs with various AAs systemically modulates their electronic properties, and this results in a tunable selectivity in detection of metal cations via fluorescence quenching. The probes can be performed in aqueous solutions around pH 7. CDs can be excited under 345 nm excitation at room temperature and exhibit fluorescent peak at 450 nm. The decreasing fluorescence intensity is directly proportional to the concentration of metal cations. The limits of detection is 8.8 mu g L-1 for Pb(II), 20 mu g L-1 for Hg(II), 3.7 mu g L-1 for Cu(II), 5.3 mu g L-1 for Zn(II), 16 mu g L-1 for Fe(III), and 7.2 mu g L-1 for Cr(III), respectively. The different fluorescence response of the AA-modified CDs can be converted to logic gates and applied to photoelectronic nanoprobes by using microprocessors. In our perception, this assay has a large potential in terms of high-throughput screening for trace amounts of metal ions.

• 出版日期2017-9