基于Mn掺杂ZnS量子点室温磷光法检测食品中兽药头孢哌酮钠残留

Determination of cefoperazone sodium residues in foods based on the room temperature phosphorescence of Mn-doped ZnS quantum dots

以水相共沉淀法合成了L-半胱氨酸(L-cys)修饰的Mn掺杂ZnS量子点(L-cys-Mn∶ZnS QDs)。基于头孢哌酮钠可通过电荷转移猝灭L-cys修饰的Mn∶ZnS量子点室温磷光的原理,建立了一种简单、快速检测食品中头孢哌酮钠微量残留的新方法。结果表明:当pH=6.4,反应时间为40 min时,量子点的磷光猝灭程度与头孢哌酮钠浓度呈良好的线性关系,线性范围为0.025~2.000μg/ml,相关系数(r)为0.9973,方法检出限为0.016μg/ml,相对标准偏差为2.3%。该方法应用于牛奶和蜂蜜中头孢哌酮钠测定的加标回收率分别为93.8%~102.1%和95.5%~99.6%。

The Mn-doped ZnS quantum dots(QDs)modified by L-Cysteine(L-cys)were prepared using water-phase coprecipitation.Based on that cefoperazone sodium could quench the room-temperature phosphorescence(RTP)of L-cys-Mn:ZnS quantum dots through charge transfer,a relatively simple and fast detection method for tracing cefoperazone sodium in food was developed.The experimental results showed that,at pH 6.4 and a reaction time of 40 min,the phosphorescence quenching degree of QDs had a linear relationship(r=0.9973)with cefoperazone sodium in the concentration range of 0.025-2.000μg/ml.The detection limit of the method was 0.016μg/ml,and the relative standard deviation was 2.3%.The method has been successfully applied for the detection of cefoperazone sodium in the milk and honey with the recoveries of 93.8%-102.1%and 95.5%-99.6%,respectively.