Iron-Imprinted Single-Atomic Site Catalyst-Based Nanoprobe for Detection of Hydrogen Peroxide in Living Cells

Abstract

Fe-based single-atomic site catalysts (SASCs), with the natural metalloproteases-like active site structure, have attracted widespread attention in biocatalysis and biosensing. Precisely, controlling the isolated single-atom Fe-N-C active site structure is crucial to improve the SASCs’ performance. In this work, we use a facile ion-imprinting method (IIM) to synthesize isolated Fe-N-C single-atomic site catalysts (IIM-Fe-SASC). With this method, the ion-imprinting process can precisely control ion at the atomic level and form numerous well-defined single-atomic Fe-N-C sites. The IIM-Fe-SASC shows better peroxidase-like activities than that of non-imprinted references. Due to its excellent properties, IIM-Fe-SASC is an ideal nanoprobe used in the colorimetric biosensing of hydrogen peroxide (H2O2). Using IIM-Fe-SASC as the nanoprobe, in situ detection of H2O2 generated from MDA-MB-231 cells has been successfully demonstrated with satisfactory sensitivity and specificity. This work opens a novel and easy route in designing advanced SASC and provides a sensitive tool for intracellular H2O2 detection.

Peroxidase-like Active Nanomedicine with Dual Glutathione Depletion Property to Restore Oxaliplatin Chemosensitivity and Promote Programmed Cell Death

“…As illustrated in Figure e, significant absorbance is not observed in the absence of DFM, indicating that an oxidation reaction did not occur in the mixed solution. However, after adding DFM NPs into the mixture solution of TMB and H 2 O 2 (pH 6.5), the color of the mixed solution changed to blue and two obvious absorbance peaks were observed through UV–vis absorption spectroscopy, which were caused by oxTMB at 370 and 652 nm, , verifying that DFM exhibits intrinsic POD-like activity. Moreover, the production of • OH increases with the increase in H 2 O 2 level, showing a dependence on H 2 O 2 concentration, which indicates that DFM can effectively induce the decomposition of H 2 O 2 effectively to produce • OH (Figure f).…”

Engineering Atomic Single Metal–FeN4Cl Sites with Enhanced Oxygen-Reduction Activity for High-Performance Proton Exchange Membrane Fuel Cells

“…In Figure a, no Fe–Fe scattering component at 2.2 Å is found in the Fourier-transformed EXAFS (FT-EXAFS) curves of FeN 4 Cl SAC and FeN x SAC, demonstrating no metallic Fe cluster and/or nanocrystal exist . The main peak of FeN x SAC is aligned with the Fe–N peak in the FePc reference sample, suggesting that Fe is dispersed as a single atom formed with Fe–N bonding . In comparison, FeN 4 Cl SAC shows a scattering path at about 1.6 Å, much closer to that of the hemin Cl reference sample.…”

Single-Atomic Site Catalyst Enhanced Lateral Flow Immunoassay for Point-of-Care Detection of Herbicide

“…The high-resolution N 1s is shown in Figure 3(h) ; the peaks near 398.4, 399.6, 401.5, and 402.5 eV can be divided into pyridinic, pyrrolic, graphitic, and oxidized N, respectively, which confirms that the nitrogen is indeed incorporated into the carbon matrix [ 42 ]. Based on binding energy, a 400.8 eV spectral valley between two main peaks of pyridinic and pyrrolic can be attributed to Fe-N x species [ 26 , 43 ]. The inset of Figure 3(h) indicates that the percentage of Fe-N x configuration is 13.2% in all doped N species.…”