The hybrid of l-cysteine and agarose can reduce HAuCl4 and support the rapid growth of plasmonic gold nanoparticles (Au NPs) in the hydrogel phase. The l-cysteine-doped agarose hydrogel (C-AGH) not only offers the substrate the capacity to reduce Au­(III) ions but also stabilizes and precisely modulates the in situ grown Au NPs with high repeatability, easy operation, and anti-interference performance. Herein, before the incubation of HAuCl4, the improved hydrogel is preincubated in the aqueous solution containing mercury ions, and the cysteine can specifically conjugate with mercury via the thiol groups. Subsequently, the responsive allochroic bands from dark blue to red can be identified in the solid hydrogel after the incubation of HAuCl4, which is attributed to the formation of regulated Au–Hg nanoamalgams. As a proof-of-concept, toxic Hg2+ ions are exploited as targets for constructing novel sensing assays based on the improved C-AGH protocol. Based on naked-eye recognition, Hg2+ could be rapidly and simply measured. Additionally, the high-throughput and trace analysis with a low limit of detection (3.7 nM) is performed using a microplate reader. On the basis of the filtering technique and remodeling of hydrogels, C-AGH working as the filtering membrane can even achieve the integration of enrichment and measurement with enhanced sensitivity. Significantly, the strategy of using an allochroic hydrogel with the staining of Au NPs can promote the rapid and primary assessment of water quality in environmental analysis.

One-to-one coupling nanostructures of Au particles and layered MoS2 are constructed. Herein, enhanced photothermal performances are promoted by the antenna effect of Au plasmonics, resulting in emerging DNA sensing assays.

Mercury ions can modulate the surface engineering effect of MoS2. Based on the cooperative optical characteristics of semiconducting MoS2 and plasmonic gold nanostructures, a novel colorimetric mercury sensing is established.

With the development and advancement, digital printing has become a leading technology. Liquid electronic ink is a kind of charged liquid ink, which is the core of HP Indigo different from others. The particle of ink is small with good color reproduction, stable physical property and the printed material widely. It is the only ink of digital printing to reproduce 95% of Pantone colors. The purpose of the experiment is getting the rheological curves in a different proportion of the original electronic ink mixed with the image oil. The impact of the proportion of image oil to the viscosity and surface tension will be got to discuss the function of the oil in printing. We mixed the ink and oil at the proportion of 1:1, 2:1, 3:1, 1:2, 1:3, and tested the steady-state rheology and dynamic rheology. The results show that with the mixture proportion changed, the viscosity change.