氮掺杂鸡毛碳点荧光关开探针用于测定百草枯

Nitrogen-doped carbon quantum dots from chicken feathers as off-on fluorescence probe for detection of paraquat

以鸡毛和乙二胺为碳源和氮源,通过一步水热法合成强荧光性能的氮掺杂碳量子点(N-CQDs),并优化其制备和掺杂条件。该碳量子点具有良好的光学、结构性质和稳定性,平均粒径7.89 nm,荧光量子产率为14%。最大激发波长为320 nm,最大发射波长为386 nm。Hg^(2+)存在条件下N-CQDs溶液的荧光被猝灭(关),添加百草枯后猝灭的荧光被恢复(开)。通过N-CQDs/Hg^(2+)体系设计了荧光"关-开"方法,在最佳条件下,百草枯在0.05~1.0μg/mL范围内具有良好的线性,线性方程为ΔF=92.41X+123.31(R^(2)=0.9989),检出限为16μg/L,加标回收率为95.3%~104.4%,RSD<3.8%。以鸡毛为原料制备的高选择性和灵敏性的荧光"关-开"探针方法可有效检测实际样品中的百草枯。

Highly fluorescent nitrogen-doped carbon quantum dots(N-CQDs)were synthesized through one-step hydrothermal method by using chicken feathers and ethylenediamine as carbon and nitrogen sources,respectively,and the preparation and nitrogen-doped conditions were optimized.The synthesized N-CQDs showed good optical properties,structural properties and stability.The average particle size was 7.89 nm,and the particles are evenly distributed.The fluorescence quantum yield reached up to 14%,and the maximum excitation and emission wavelength were 320 nm and 386 nm,respectively.Results showed that the fluorescence of N-CQDs solution was quenched in the presence of Hg^(2+)ions(turn off),and the quenched N-CQDs/Hg^(2+)system was recovered after addition of paraquat(turn on).Based on that,a simple and rapid fluorescence off-on approach for detection of paraquat was designed by using N-CQDs/Hg^(2+)system.Under the optimal conditions,the linear equation isΔF=92.41 X+123.31(R^(2)=0.9989)with the good linear relation range of 0.05-1.0μg/m L and the detection limit of 16μg/L.The recoveries of paraquat were between 95.3%and 104.4%with RSD<3.8%.The highly selective and sensitive fluorescence off-on approach can be used to for the determination of paraquat in real samples.