以碳量子点为过氧化物模拟酶的葡萄糖测定方法

Determination of Glucose Based on Carbon Quantum Dots as Peroxidase Mimetic Enzyme

以烟炱为原料制备水溶性碳量子点(CQDs),此碳量子点具有过氧化物模拟酶活性,可催化H_2O_2氧化3,3',5,5'-四甲基联苯胺(TMB)产生显色反应,而葡萄糖氧化酶(GOx)可催化葡萄糖氧化产生H_2O_2,基于上述原理,建立了一种以CQDs为过氧化物模拟酶的葡萄糖测定方法。以TMB为底物,研究了温度、p H值等条件对催化性能的影响。结果表明,pH 3.5、35℃、0.5 mmol/L TMB、1μg/mL CQDs时,此方法检测葡萄糖的线性范围为0.025~0.40 mmol/L,检出限为5.10μmol/L(S/N=3),尿液中的常见干扰物不干扰测定。实际尿液中的加标回收率为95.0%~105.1%。

Water soluble carbon quantum dots （CQDs） were prepared by using soot as carbon source. Theobtained CQDs showed an excellent intrinsic peroxidase-like activity, which could catalyze the oxidization of3,3＇,5,5＇-tetramethylbenzidine （TMB） by H2O2 and thus resulted in color change. Glucose could react withdissolved oxygen to produce H2O2 in the presence of glucose oxidase （GOx）. A colorimetric method usingCQDs as peroxidase mimetic enzyme was developed for glucose determination. When TMB was acted as asubstrate, the effect of a series of conditions, such as temperature and pH on the catalytic activity of theobtained CQDs, was systematically studied. Under optimal conditions, e. g. pH 3. 5 and temperature 35益,0. 5 mmol / L TMB and 1 μg / mL CQDs, the absorbance at 652 nm showed linear response with glucoseconcentrations ranging from 0. 025 mmol / L to 0. 40 mmol / L, with detection limit of 5. 10 μmol / L （3σ/ k）.The proposed method exhibited excellent selectivity and the common substances did not interfere with detectionof glucose. This method was successfully applied to detect glucose in real samples with recoveries of 95. 0% -105. 1%.