花椒碳点荧光探针的制备及对牛奶中溴代乙酰胆碱的检测

以食用花椒为原料,采用热解法制备了荧光碳量子点(CDs),加入β-环糊精修饰CDs.用荧光表征CDs的光学性质,透射电镜观察了CDs的外貌特征.结果表明:荧光激发和发射波长分别为315 nm、429 nm,荧光量子产率为0.60,碳点平均直径为4.2 nm,由于溴代乙酰胆碱(ACH)对碳量子点的荧光具有增敏作用,可以用于牛奶中ACH的分析检测.在pH值为7,25 ℃条件下,(ACH)的加入量与CDs荧光强度的增加成正比,其线性回归方程为ΔF=314.72c+134.54,线性0.08~1.6 μmol/L,相关系数 r=0.997 9,标准偏差为1.75,检出限(3σ/K)为1.62×10^-8 mol/L.将此方法用于牛奶和酸奶中ACH含量的测定,回收率为98%~102%.

Preparation of carbon quantum dot fluorescence probe with prickly ash and detection of acetylcholine in milk

Fluorescent carbon quantum dots(CDs)were prepared from edible prickly ash by pyrolysis method and CDs was further modified β-CD. The optical properties and macroscopic features of CDs were respectively characterized by fluorescence spectroscopy and transmission electron microscopey(TEM). The results showed that the wavelength of fluorescence excitation and emission were at 315 nm and 429 nm, respectively. The fluorescence quantum yield was 0.60 and the average diameter of the carbon dots was 4.2 nm. Owing to acetylcholine bromide can sensitize the fluorescence of carbon quantum dots, it can be used for the analysis and detection of acetylcholine bromide in milk. With the pH7.0 and the temperature is 25 ℃, the fluorescence intensity is proportional to the amount of acetylcholine bromide, the linear regression equation is ΔF=314.72c+134.54, the linear range is from 0.08 to 1.6 μmol/L, r=0.997 9, the standard deviation is 1.75, and the detection limit is 1.62×10^-8mol/L. This method was used to detect the acetylcholine content in milk and yogurt, and the recovery rate is between 98% and 102%.