A Chiral Sensing\nPlatform Based on a Starfish-Shaped\nAuCu Alloy for Chiral Analysis

Designing\nalloys with intrinsic chirality for chiral\nanalysis is\nan interesting subject, since most alloys are achiral. Here, a starfish-shaped\nAuCu alloy is facilely prepared through simultaneous reduction of\nchloroauric acid (HAuCl<sub>4</sub>) and copper chloride (CuCl<sub>2</sub>) by l-ascorbic acid (l-AA). The resultant\nAuCu alloy exhibits fascinating chirality due to the chiral lattice\ndistortion generated in the alloy. More interestingly, the chirality\nof the AuCu alloy is exactly opposite to that of Au nanoparticles\n(AuNPs) and Cu nanoparticles (CuNPs) prepared through the reduction\nof HAuCl<sub>4</sub> and CuCl<sub>2</sub> by l-AA. Additionally,\nthe AuCu alloy also has good electrical conductivity, and thus, it\nis used in the construction of the electrochemical chiral sensing\nplatform for chiral analysis. The tryptophan (Trp) enantiomers can\nbe discriminated with the AuCu alloy-based chiral sensing platform.\nMoreover, this chiral sensing platform can also be used for the detection\nof l-Trp in the concentration ranging from 10 nM to 10 mM\nwith a limit of detection (LOD) of 3.12 nM.