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Updated: Jul 16, 2025
Manganese Oxide Nanoparticle Synthesis by Thermal Decomposition of ManganeseII Acetylacetonate
Published on: June 18, 2020
Manganese dioxide nanosheet-modulated ratiometric fluoroprobe based on carbon quantum dots from okra for selective
He Mei1, Xiaolei Zhu2, Ziqian Li2
1Zhejiang Provincial Key Laboratory of Watershed Science and Health, College of Public Health and Management, Wenzhou Medical University, Wenzhou 325035, China; South Zhejiang Institute of Radiation Medicine and Nuclear Technology, Wenzhou Medical University, Wenzhou 325014, China.
Abstract:
Herein, we developed a ratiometric fluoroprobe by integrating okra-derived carbon quantum dots (CQDs) with amplex red (AR) using manganese dioxide nanosheets (MnO2 NSs) as a medium. Fluorescence intensities (FIs) of CQDs were sharply quenched by MnO2 NSs via an inner-filter effect processes, whereas the FIs of AR were significantly enhanced due to oxidation of AR to AR-ox by the oxidase-mimetic activity of MnO2 NSs. Acetyrylcholinesterase hydrolyzed acetylthiocholine to produce thiocholine, and the decomposition of MnO2 NSs to Mn2+ by thiocholine led to the FI recovery of CQDs, but decreased FIs of AR-ox. Based on the above phenomenon and the inhibitory effect of dichlorvos (DDVP) on acetyrylcholinesterase activity, a novel ratiometric fluoroprobe for DDVP quantification was pioneered. Under optimized conditions, this fluoroprobe gave a wide linear range (4-120 μg/L), low detection limit (1.2 μg/L), and satisfactory fortification recoveries (90.0-110.0%), thereby providing good prospects for routine DDVP monitoring in foods.
