Stabilizing Chiral Gold Nanorods from Chiral-Micelle-Directed Synthesis by Sulfide Treatment for Chiroplasmonic Sensing

As a typical chiroplasmonic nanomaterial, chiral gold (Au) nanorods (NRs) synthesized using chiral micelles have been facing the issue of chiroptical instability. Herein, a strategy that can effectively enhance the chiroptical stability of chiral Au NRs is demonstrated in which sodium sulfide (Na2S) is introduced to the system. Taking advantage of the stable chiral Au NRs, a sensitive detection of alkaline phosphatase is also demonstrated. This work not only provides an effective way for solving the obstacle of thermodynamic instability in chiroplasmonic nanostructures but also facilitates the practical application of chiral Au NRs and broadens their potential in chiroplasmonic sensing.