Novel ultrasensitive Raman assay method based on enzyme mimetics for ultra trace of HO.

Enzyme mimetics have been widely applied on HO assay, but it is still challenging and interesting to realize the sensitive detection for ultra-trace HO. Here, an ultrasensitive Raman assay method based on novel WO@IP6-Fe enzyme mimetics with peroxidase-like activity was established. WO microspheres (MSs) were found to have weak peroxidase-like activity, and the combination of IP6-Fe and WO can produce stronger activity.

Self-assembled CrO@nanogel/Au nanozymes to simulate peroxidase activity as a HO sensor.

The low temperature solvothermal method synthesized CrO NPs has not only peroxidase activity, but also oxidase activity. Then, the oxidase activity of CrO NPs is effectively shielded by nanogel immobilization using three monomers acrylamide, NIPAAM (N-isopropylacrylamide) and MBA (N,N'-methylene bisacrylamide) in HEPES (4-(2-hydroxyerhyl)piperazine-1-erhanesulfonic acid) buffer. Ultimately, the enzymatic activity of CrO@nanogel/Au is significantly enhanced after doping Au NPs by SERS (Surface Enhanced Raman Spectroscopy) evaluation.

Synergistic function of Au NPs/GeO nanozymes with enhanced peroxidase-like activity and SERS effect to detect choline iodide.

A novel Au NPs/GeO nanozymes are developed as Surface-Enhanced Raman Scattering (SERS) substrates with the promising prospect for detection ChI. Herein, it is discovered that both Au NPs and GeO nanozymes have peroxidase-like activity, catalyzing colorless 3,3',5,5'-tetramethylbenzidine (TMB) to produce blue TMB. Interestingly, compared with single Au NPs or GeO nanozymes, the Au NPs/GeO nanozymes show stronger peroxidase-like activity, and significantly ameliorated SERS signal of TMB.

A facile SERS strategy to detect glucose utilizing tandem enzyme activities of Au@Ag nanoparticles.

Surface-Enhanced Raman Scattering (SERS) is a powerful analysis technology, attracting more and more attention due to its high sensitivity and selectivity. Herein, we report a simple seed-mediated method to synthesize Au@Ag nanoparticles (NPs) as a multifunctional biosensor for the label-free detection of hydrogen peroxide (HO) and glucose by SERS. Au@Ag NPs, as an ultrasensitive SERS substrate, show the dual activities (peroxidase-like and GOx-like activities).

Simultaneous identification of contaminant sources and hydraulic conductivity field by combining geostatistics method with self-organizing maps algorithm.

In the contaminant remediation of groundwater, the release history of contaminant sources and hydraulic conductivity field are two key parameters that need to know, but their actual values are difficult to obtain and can only be inversely identified by limited measured data. However, the process of solving the inverse problem needs to repeatedly call the forward model of contaminant transport, which is very time-consuming, especially for the high-dimensional inverse problems. In this study, based on the training data generated from a prior range of parameters (the release strength of contaminant sources and hydraulic conductivity at pilot points), the self-organizing maps (SOM) algorithm was employed to construct the surrogate model for the numerical model of contaminant transport in a simplified hypothetical aquifer, then the surrogate model was used to retrieve jointly the contaminant strength of sources and the hydraulic conductivity at pilot points, and the Kriging method of geostatistics was further used to process the estimated K-values at pilot points to obtain the hydraulic conductivity field.