Inner filter effect-modulated ratiometric fluorescence aptasensor based on competition strategy for zearalenone detection in cereal crops: Using mitoxantrone as quencher of CdTe QDs@SiO 2

• Published in: Food chemistry 2021-07, Vol.349, p.129171
• Main Authors: Bi, Xiaoya, Li, Libo, Liu, Xiaohong, Luo, Lijun, Cheng, Zhiliang, Sun, Jinying, Cai, Zhibin, Liu, Jinming, You, Tianyan
• Format: Article
• Language: English
• Subjects: Aptamers, Nucleotide; Cadmium Compounds - chemistry; Crops, Agricultural - chemistry; Edible Grain - chemistry; Flour - analysis; Fluorescence; Graphite; Limit of Detection; Mitoxantrone - chemistry; Quantum Dots - chemistry; Silicon Dioxide - chemistry; Tellurium - chemistry; Zearalenone - analysis
• ISSN: 1873-7072

Herein, an innovative ratiometric fluorescence (FL) aptasensor was successfully fabricated for the accurate analysis of zearalenone (ZEN) in corn and barley flour. The ZEN aptamer-modified nitrogen doped graphene quantum dots (NGQDs-apt) and silica sphere-encapsulated cadmium telluride quantum dots (CdTe QDs@SiO ) were directly mixed and applied as ratiometric probes. In the absence of ZEN, mitoxantrone (MTX), which was innovatively introduced as quencher, was captured by NGQDs-apt and its inner filter effect (IFE) on CdTe QDs@SiO was inhibited. When ZEN existed, MTX separated from NGQDs-apt and re-dispersed around CdTe QDs@SiO owing to the competitive binding of ZEN with its aptamer. As the IFE of free MTX on CdTe QDs@SiO recovering, the FL intensity of CdTe QDs@SiO was quenched, while the FL intensity of NGQDs-apt was nearly invariant. On this basis, a ratiometric FL aptasensor for ZEN was fabricated, which exhibited outstanding detection performances with a desirable detection limit of 0.32 pg mL .