Geometric Tuning of Single‐Atom FeN₄ Sites via Edge‐Generation Enhances Multi‐Enzymatic Properties

Abstract

Single‐atom nanozymes (SAzymes) are considered promising alternatives to natural enzymes. The catalytic performance of SAzymes featuring homogeneous, well‐defined active structures can be enhanced through elucidating structure‐activity relationship and tailoring physicochemical properties. However, manipulating enzymatic properties through structural variation is an underdeveloped approach. Herein, the synthesis of edge‐rich Fe single‐atom nanozymes (FeNC‐edge) via an H2O2‐mediated edge generation is reported. By controlling the number of edge sites, the peroxidase (POD)‐ and oxidase (OXD)‐like performance is significantly enhanced. The activity enhancement results from the presence of abundant edges, which provide new anchoring sites to mononuclear Fe. Experimental results combined with density functional theory (DFT) calculations reveal that FeN4 moieties in the edge sites display high electron density of Fe atoms and open N atoms. Finally, it is demonstrated that FeNC‐edge nanozyme effectively inhibits tumor growth both in vitro and in vivo, suggesting that edge‐tailoring is an efficient strategy for developing artificial enzymes as novel catalytic therapeutics.

Bioinspired FeN5 Sites with Enhanced Peroxidase-like Activity Enable Colorimetric Sensing of Uranyl Ions in Seawater

“…FeN 5 –SA has smaller K m values and higher V max values than FeN 4 –SA, contributing to better affinity ability and higher catalytic performances. Besides, based on the previous works, nanozymes always have both OD and POD-like activities. , The OD-like activity would activate dissolved oxygen in the system and interfere with the accuracy of colorimetric sensing. Therefore, the OD-like activity of the two nanozymes was also investigated.…”

Co Single-Atom Nanozymes for the Simultaneous Electrochemical Detection of Uric Acid and Dopamine in Biofluids

“…With enzyme-like activity and high active site density, transition metal and nitrogen-codoped carbon (M–N-C) materials have been studied and proven to show promising applications in single-atom catalytic sensing. , The M–N x site catalyzes efficiently in redox reactions through its unique geometry/electronic structure. , Kim and others have obtained FeN x nanozymes with multiple enzymatic activities by vacuum pyrolysis and have used for tumor growth inhibition. Cheng and colleagues have prepared FeN x nanozymes with excellent peroxidation activity by combining single-atom Fe with carbon nanotubes.…”

“…20,21 The M−N x site catalyzes efficiently in redox reactions through its unique geometry/electronic structure. 21,22 Kim and others 23 have obtained FeN x nanozymes with multiple enzymatic activities by vacuum pyrolysis and have used for tumor growth inhibition. Cheng and colleagues 24 have prepared FeN x nanozymes with excellent peroxidation activity by combining single-atom Fe with carbon nanotubes.…”

Electron Lock Manipulates the Catalytic Selectivity of Nanozyme

“…Nanozymes, defined as nanomaterials with enzyme-mimicking functions, are creating a desirable era of biocatalysis by leveraging the power of nanotechnology. − As next-generation artificial enzymes, nanozymes have aroused significant attention in biomedical fields, − ranging from advanced sensing to potent drugs and even elaborate artificial organelles to perform programmed cascade reactions. − Despite advantages of stability, mass production, and catalytic activity comparable to that of natural enzymes, − intrinsically low selectivity raises an enormous challenge in their ongoing development. Most reported nanozymes have multiple enzymatic activities since they indiscriminately bind and catalyze various substrates, typically an arrangement of different oxidoreductases. − Selectivity deficiency has evoked debates on nanozyme as enzyme mimics ,, and a series of difficulties involving detection sensitivity, off-target biotoxicity, and cascade catalysis efficiency. Thus, developing strategies to manipulate nanozyme selectivity poses significant challenges.…”