Synthesis And Application Of Fluorescent Copper Nanoclusters Templated By Thymine

Metal nanoclusters（NCs）,composed of a few to a hundred atoms provide the missing link between atomic and nanoparticle behavior in metals,their dimensions approach to the Fermi wavelength of electrons,resulting in molecular-like properties,such as well-defined molecular structures,HOMO-LUMO transitions,and strong photoluminescence（PL）.These unique properties offer great possibilities in exploring their potential applications in sensing,catalysis and bioimaging.Cu NCs has become an active research area because of the low cost and the similar optical property between non-noble metal Cu NCs and noble metal NCs.This work has successfully prepared fluorescent Cu NCs and constructed sensors based on Cu NCs for sensing metal ions and small moleculars closely related to human healthy.The main contents are listed as follows:First,a strategy using Thymine as template to rapid synthesis of fluorescent and water-soluble Cu NCs has been developed for the first time.The characterization demonstrate that Cu NCs@T exhibited a intensive yellow fluorescence emission at 561 nm under excitation at 370 nm,with average diameter of 2.8 nm and an average lifetime 9.9 μs.XPS imply that Cu（0）and Cu（I）are co-existence.In addition,Cu NCs@T exhibit excellent Salt resistance and good photo stability.So,these outsanding properties of Cu NCs@T indicating the promising application in bioanalysis.Then,based on the prepared Cu NCs@T,we constructed "turn-off" fluorescent sensor to detect glucose and uric acid.The results showed that the fluorescence of Cu NCs@T quenching after adding H2O2.So,we detected glucose and uric acid indirectly based on glucose oxidase and uricase sensor.The introduction of the enzyme increased the selectivity of sensors.The linear range of glucose and uric acid is 100 μmol/L-1.5 mmol/L and 0.8-2 mmol/L respectively.At last,we constructed "turn-on" fluorescent sensor to detect Mn²⁺ rapidly and sensitively.Through literature research,this is the first time to detect Mn²⁺ in the "turn-on" strategy using Cu NCs.The fluorescence of Cu NCs@T enhanced greatly and the emission wavelength red-shifted after adding Mn²⁺.It is interesting to note that Cu NCs@T-Mn²⁺ complex show stability in wide pH range and better photo stability compared with Cu NCs@T.The linear range of Mn²⁺ was 100-250 μmol/L and the limit of detection was 10 μmol/L.Moreover,the novel "turn-on" fluorescent sensor was applied to detect Mn²⁺ in real samples.