A rapid method for the detection of humic acid based on the poly(thymine)-templated copper nanoparticles

This work described a new method for the detection of humic acid（HA） based on the poly（thymine）(polyT)-templated copper nanoparticles（CuNPs）. Without the presence of HA, the formation of poly Ttemplated CuNPs could take place, resulting in strong fluorescence emission peaks at 610 nm（upon excitation at 340 nm）. On the other hand, when HA was present, strong interaction between HA and Cu;took place, which then hampered the effective formation of fluorescent CuNPs, leading to the decrease in fluorescence intensity. Furthermore, under the optimal experimental conditions, the method exhibited a high specificity to HA with a detection limit of 0.4 mg/L. This work has demonstrated a low-cost and convenient method that could be accomplished within 10 min. The method could provide a simple, rapid,and sensitive fluorescent platform for the detection of HA.