Mercury ion-engineering Au plasmonics on MoS₂ layers for absorption-shifted optical sensors

Semiconducting MoS₂ layers offer the electrons, reducing conjugated Au(I) to Au atoms, and sebsequently serve as desirable substrates for supporting the interfacial growths of gold nanostructures. Au-covering MoS₂ heterostructures perform morphology-varied optical characteristics, and the surface engineering of MoS₂ involved by Hg²⁺ ions results in the differential growths of nanostructures and morphological diversities. Naked-eye colorimetric responses to mercury ions, with a low limit of detection of 1.27 nM, are achieved based on the in situ grown heterostructures.