A ratio fluorescence method based on dual emissive gold nanoclusters for detection of biomolecules and metal ions

Gold nanoclusters have good biocompatibility and can be easily modified to improve their luminescence properties. In this study, we prepared a new type of dual-emitting gold nanoclusters (d-Au NCs) for discriminative detection of phenylalanine and Fe(3+) with high selectivity and sensitivity. The fluorescence sensor which was synthesized without any further assembly or conjugation shows dual-emissions at 430 nm and 600 nm under a single excitation at 350 nm. Phenylalanine can turn on the red emission of the probe, while Fe(3+) can turn on its yellow emission and turn off the red emission. By detecting a variety of amino acids and metal ions, d-Au NCs showed good selectivity to phenylalanine and Fe(3+). Finally, this method was applied to determine phenylalanine and Fe(3+) in lake water, human urine and milk, which has certain application prospects in the field of biology and environment.