期刊论文

Yang, Decai;Zhang, B;Gu, Yanjuan;Wong, WT;Jiang, LJ

英文

Chemical Engineering Journal

1385-8947

2023

474

145675

10.1016/j.cej.2023.145675

As demonstrated by the DFT results, the Fe/Mn@PSe3 nanocomposites with Fe and Mn at a molar ratio of 1:1 can efficiently catalyze H2O2 to ·OH and O2 simultaneously, thus enabling the bidirectional activation of H2O2 as illustrated in Fig. 3A. Single-atom catalyst Fe@PSe3 and Mn@PSe3 was also prepared to study and compare their catalytic activity in producing ·OH and O2. 3,3′,5,5′-tetramethylbenzidine (TMB) was used as a probe to detect the production of ROS by colorimetric reaction, as it can be oxidized by ROS to oxTMB with absorption maximum at 652 nm. Absorbance spectrum of different treatment groups in simulated TME was measured using a UV–vis spectrophotometer (Fig. S8). As can be seen, a greater ROS generation is seen with Fe/Mn@PSe3 than Mn@PSe3 or Fe@PSe3, verifying equal portions of Fe and Mn can efficiently catalyze H2O2 to produce ROS and can be further enhanced under laser irradiation. To make the enzymatic reaction mechanism of Fe/Mn@PSe3 clear, we further checked the generation of active intermediate by ESR spectroscopy, where 5,5-dimethyl-1-pyrroline N-oxide (DMPO) was employed as the trapping agent. As shown in Fig. 3H, ·OH is the main product during the catalytic process, and when compared with different treatment groups, a similar trend was shown, confirming that Fe/Mn@PSe3 exhibits the optimal reaction barriers to catalyze H2O2 to generate ·OH. Enzymatic kinetic experiments were also conducted according to procedures described in the literature [27], [28], [29]. Fe/Mn@PSe3 exhibited good POD-like catalytic activity at pH 6.5, Michaelis-Menton constant (Km) and maximum reaction rate (Vmax) of Fe/Mn@PSe3 at pH 6.5 were measured to be 0.17 mM and 2.73 × 10-8 M s−1, respectively (Fig. S9). Catalytic production of O2 by Fe/Mn@PSe3 was also measured with the comparison to the two single-atom catalysts. As shown in Fig. 3I, a greater amount of O2 is produced upon treatment with Fe/Mn@PSe3 than Mn@PSe3 or Fe@PSe3, which suggests Fe/Mn@PSe3 has better catalytic activity towards O2 production, indicating it has a potential role in alleviating tumor hypoxia.

本校为通讯机构

Tumor therapy employing metal-based nanomaterials to convert the abundant H2O2 in tumor microenvironment (TME) to oxygen (O2) and hydroxy radical (& BULL;OH) has attracted substantial attention. However, the generally complex structure of metal nanosystems may have poor catalytic selectivity towards the target and hence cause undesired side reactions. Single-atom catalysts (SACs) with high atomic utilization, composition of identical active site and tunable reaction pathway can be harnessed to realize the well-controlled and highly-selective conversion of H2O2 for cancer therapy. Herein, a ser...