Target-triggered Fe3O4@NPC-UCNPs assembly for photoactivatable biosensing of Aflatoxin B1

作者：Xu, Zhou; Yu, Shaoyi; Xie, Xinyi; Li, Qingxia; Ding, Li; Chen, Maolong; Tu, Jia; Xing, Keyu^*; Cheng, Yunhui^*

来源：Chemical Engineering Journal, 2023, 470: 144028.

DOI：10.1016/j.cej.2023.144028

• Aflatoxin B1
• Assembly
• Fluorescence biosensor
• Magnetic nanoporous carbon
• Upconversion nanoparticles

Herein, target-triggered magnetic nanoporous carbon-upconversion nanoparticles (Fe3O4@NPC-UCNPs) assembly as photoactivatable nanozymes were first used to build a novel fluorescence biosensor for sensitive detection of aflatoxin B1 (AFB1). In this study, the catalytic activity of Fe3O4@NPC was combined with heterostructure physical property of Fe3O4@NPC and optical property of UCNPs by immune recognition. The UCNPs absorbed near infrared light and transferred energy to Fe3O4@NPC, induced the separation of electron-hole pairs on the heterostructure, resulting in the generation of hydroxyl free radical (center dot OH). The Fe3O4@NPC-UCNPs assembly nanozymes could oxidize 2 ',7 '-dichlorodihydrofluorescein (DCFH) into 2 ',7 '-dichlorofluorescein with a high fluorescence intensity by center dot OH and showed high affinity to DCFH (K-m = 0.0799 mM). The designed fluorescence biosensor allowed quantitative detection as low as 0.56 pg/mL with a wide linear range of detection from 0.1 to 10 ng/mL. The light-activated Fe3O4@NPC-UCNPs assembly could take O-2 as an oxidant to oxidate the substrate, avoiding the using of unstable H2O2 and endowing higher accuracy in biosensing applications.

• 单位
  长沙理工大学