Single crystal nanoplates with thickness less than 30 nm, characterized by hexagonal and truncated triangular shapes bounded mainly by {111} facets, were obtained in large quantities by aspartate reduction of gold chloride.

Water-soluble and red-emitting gold nanoclusters (Au NCs) were synthesized with single-stranded DNA as a promising biotemplate and dimethylamine borane as a mild reductant. The fluorescent Au NCs can be formed in a weakly acidic aqueous solution that is free from the simultaneous formation of large nanoparticles. The cluster feature of the formed Au species has been revealed by fluorescence spectra, absorption spectra, and transmission electron microscopy. Additionally, DNA sequences could be used to tune the Au NCs' emissions. The as-prepared Au NCs display high stability at physiological pH condition, and thus, wide potential applications are anticipated for the biocompatible fluorescent Au NCs serving as nanoprobes in bioimaging and related fields.

Double-stranded DNAs (ds-DNAs) have been identified as efficient templates favoring the formation of fluorescent copper nanoparticles (Cu NPs). Herein, we have tried to synthesize fluorescent Cu NPs using single-stranded DNAs (ss-DNAs) as templates and to identify the critical DNA sequences. By comparing the results using homopolymer DNAs, hairpin DNAs, and pristine ss-DNAs as templates, we found that DNA thymine base plays a dominant role in producing red-emissive fluorescent Cu NPs on ss-DNA templates. The thymine-dependent growth of the fluorescent Cu NPs is confirmed by Hg2+ mediated T–T base pair in comparison with the other non-specific metal ions, which could be developed into a practical sensor for turn-on fluorescence detection of Hg2+ with a high selectivity. The mechanism is briefly discussed according the DNA sequence-dependent formation of fluorescent Cu NPs. This work demonstrates the sequence role in producing fluorescent Cu NPs that could serve as promising fluorescent nanoprobes in biosensing and DNA-hosted Cu nanomaterials.