Hg2+-activated oxidase-like activity of Ag2S@graphene oxide nanozyme and its naked-eye monitoring Hg2+ application with obvious hyperchromic effect

Ag-β-Cyclodextrin-Graphene Oxide Ternary Nanostructures with Peroxidase-Mimicking Activity for Hg2+ Detection

“…As for the no obvious XRD peak found from the component of GO in the present Ag-β-CD-GO, it can be attributed to the intermediate Ag-β-CD being fixed tightly onto the GO matrix. Accordingly, GO sheets could not arrange regularly to be amorphous. , …”

“…By virtue of the superior physicochemical properties, such as excellent thermal stability, facile preparation, low consumption, and notable catalytic performance, nanosized composites have attracted much more extensive attention recently. − Since the first report by Yan et al, a series of noble metal-based nanomaterials with various sizes, morphologies, and compositions have been developed, such as noble metals, , alloys, , metal sulfides, , metal oxides, , and metal–organic frameworks, , expressing excellent enzymelike catalytic activity. Among all of the noble metal-based nanozymes identified, various nano-Ag-based enzyme-mimicking sensors were developed as multifunctional amplifiers for analytical applications, such as Au@Ag, Au@Ag@Pt, DNA-Ag/Pt nanoclusters, Fe 3 O 4 @MoS 2 -Ag, and Ag-CoFe 2 O 4 /reduced graphene oxide nanocomposites .…”

“…Accordingly, GO sheets could not arrange regularly to be amorphous. 11,28 The strong interaction among AgNPs, β-CD, and GO could also be inferred from their FTIR spectra. As shown in Figure 1g, the transmission peaks at 3385, 1640, and 1023 cm −1 for free β-CD and the peaks at 3429, 1629, and 1065 cm −1 for free GO result from the stretching vibrations of O−H, CO, and C−O bonds in β-CD or GO, respectively.…”

“…An excellent partitioned linear relationship between A 653 and c Hg 2+ is observed, i.e., from 0.4 to 20.0 × 10 −8 mol•L −1 (Figure 7b) with a linear equation of A 653 = 0.44376−0.01505 c Hg 2+ (R 2 = 0.9421) and from 20.0 to 120.0 × 10 −8 M with a linear regression equation of A 653 = 0.2228−0.0011 c Hg 2+ (R 2 = 0.9911). According to the definition of the limit of detection (LOD), 11,54 3 times of the standard deviation of A 653 for 20 blank samples without Hg 2+ used here, the LOD for the visual detection of Hg 2+ was deduced to be 8.3 × 10 −10 mol•L −1 (S/N = 3), far below the ultimate value of 3.0 × 10 −8 mol•L −1 permitted by the WHO in drinking water. 55 In addition, it expresses a lower LOD or larger linear range for Hg 2+ detection than those reported previously by similar colorimetric analyses (Table S4).…”

Hydrogen Bond-Assisted Colorimetric Picomolar Level Detection of Hg2+ Ions in 100% Aqueous Solution

“…Very few reports on the colorimetric detection of Hg 2+ and Ag + using nanomaterial-based sensors viz. gold nanoparticles, − silver nanoparticles, − Pt nanocubes, and chromophoric polydentate ligands are available . Among them, only handful of materials were able to reach the picomolar level detection of Hg 2+ and Ag + ions. ,, Preparation of an organic dye molecule (D–A) with a higher molar extinction coefficient (ε) may improve the sensitivity in colorimetric detection.…”