中文摘要：

采用一步水热法合成了水溶性N-乙酰-L-半胱氨酸修饰的碲化镉量子点（NACCdTe）,基于甲醛对该量子点的荧光猝灭作用,建立了测定甲醛的荧光光谱法。在7.5×10^-8 mol·L^-1 NAC-CdTe-0.01mol·L^-1 Tris-HCl（pH 6.0）体系中加入不同质量浓度的甲醛溶液,反应10min后,以400nm为激发波长,于567nm处测量体系的荧光强度（I）。甲醛的质量浓度在5.0×10^-6-1.0×10^-1 g·L^-1内与I0/I（I0为不加甲醛时体系的荧光强度）值呈线性关系,检出限（3s/k）为1.3×10^-6g·L^-1。方法用于测定水样中的甲醛,测定结果与乙酰丙酮分光光度法的测定结果相符,加标回收率在98.0%-102%之间,测定值的相对标准偏差（n=5）在1.4%-4.1%之间。

英文摘要：

Water-soluble CdTe quantum dots （QDs） modified with N-acetyl-L-cysteine （NAC） are synthetized by one-step hydrothermal method.Based on the fluorescence quenching of formaldehyde to NAC-CdTe QDs,fluorescence spectrometry for determination of formaldehyde was developed.Formaldehyde with different mass concentration was added into the system with 7.5×10-8 mol·L^-1 NAC-CdTe and 0.01mol·L^-1 Tris-HCl （pH 6.0）.After reaction for 10 min,the fluorescence intensity（I）of the system was measured at 567 nm with the excitation wavelength of 400 nm.Linear relationship was found between the value of I0/I（I0 was the fluorescence intensity of the system without formaldehyde）with the mass concentration of formaldehyde in the range of 5.0×10^-6-1.0×10^-1 g·L^-1,with detection limit （3s/k） of 1.3×10^-6g·L^-1.The poposed method was applied to detemination of formaldehyde in water sample,giving results in consistent with those obtained by acetylacetone spectrophotometric method.Recovery rates obtained by standard addition method were in the range of 98.0%-102%,and RSDs （n=5） were in the range of 1.4%-4.1%.