硅掺杂碳量子点荧光猝灭法测定水样中铜(Ⅱ)

3-氨丙基三甲氧基硅烷(APTMS)与戊二醛(GA)混合前驱物合成的硅掺杂碳量子点(SDCQDs),其最大吸收、激发和发射波长分别为259,245,395 nm,量子产率为13.60%,XPS谱图表明碳量子点掺杂Si,且富含甲亚胺基团和硅氧键。Cu~(2+)对碳量子点荧光产生猝灭作用,依据Cu~(2+)浓度与碳量子点荧光强度猝灭率的相关性,建立碳量子点荧光探针测定水样中Cu~(2+)的分析方法,其它金属离子对Cu~(2+)干扰程度较小,回收率为91.4%~100.8%,检出限为0.13μmol/L,相对标准偏差为0.20%~0.92%。

Determination of Copper Ions in Water Samples by Silicon Doped Carbon Quantum Dots

The silicon doped carbon quantum dots(SDCQDs) were synthesized using 3-aminopropyl-trimethoxysilane(APTMS) and glutaraldehyde(GA) as mixed precursors.The maximum absorption wavelength,fluorescence excitation and fluorescence emission wavelengths of the SDCQDs were 259 nm,245 nm and 395 nm,respectively.The quantum yield of SDCQDs was 13.60%.The XPS spectra showed that the quantum dots were rich in azomethine group and silicon oxygen bond.The fluorescent intensity of SDCQDs could be quenched by copper ions.Hence,on the basis of the relationship between fluorescence quenching ratio and concentrations of copper ions,a method was developed for the determination of copper ions in water samples by using silicon doped carbon quantum dot as fluorescent probe.Other metal ions had no function of quenching.The spiked recoveries were in the range of 91.4%-100.8%,the detection limit was 0.13 μmol/L and the relative standard deviations(RSDs) were in the range of 0.20%-0.92%.