采用N-CQDs-Al3+探针检测两类食品中三聚磷酸钠

通过烟酰胺一步水热法制备氮掺杂碳量子点(N-CQDs),该碳量子点荧光量子产率为23. 2%。TEM和XPS结果表明,其平均粒径为2 nm及表面可能存在-COOH和-NH2。基于Al3+对N-CQDs荧光猝灭和三聚磷酸钠(STPP)能显著恢复其荧光强度的原理,设计一种新型荧光探针用于检测STPP。该方法的线性范围为0. 33~9. 33μmol/L,检出限为0. 19μmol/L。该探针可用于检测牛奶和猪皮晶中STPP。

Detection of sodium tripolyphosphate in two kinds of food by N-CQDs-Al3+ probe

Nitrogen doped carbon quantum dots( N-CQDs) were prepared by one-step hydrothermal method with nicotinamide( Nic) as the only raw material,and its fluorescence( FL) quantum yield was 23. 2%. The results of TEM and XPS showed that the average particle size of N-CQDs was 2 nm and the groups of-COOH and-NH2 might be existed on its surface. Based on the effective FL quenching of N-CQDs by Al3+( turn off) and its FL intensity remarkable recovery by STPP( turn on), a new probe was designed to detect sodium tripolyphosphate( STPP). The linear range and limit of detection of the method were 0. 33-9. 33 μmol/L and0. 19 μmol/L,respectively. The probe was successfully used to detect STPP in milk and pigskin crystals.