摘要
以果皮为原料制备了水溶性碳量子点(CQDs),透射电子显微镜分析表明其平均粒径为2.4 nm;红外光谱分析证实CQDs表面富含含氧官能团.所得CQDs可催化H_(2)O_(2)氧化3,3’,5,5’-四甲基联苯胺(TMB)生成蓝色氧化产物(ox-TMB).基于上述反应,建立了测定H_(2)O_(2)的分析方法,在pH=3.5,温度40℃,TMB浓度为1.0 mmol/L及孵育时间15 min的条件下,当H_(2)O_(2)浓度在5.0~100μmol/L范围时,ox-TMB的吸光度随H_(2)O_(2)浓度的升高而线性增强,方法的检出限为3.0μmol/L.鉴于H_(2)O_(2)是肌氨酸氧化酶催化肌氨酸氧化的产物之一,建立了CQDs催化H_(2)O_(2)氧化TMB间接测定肌氨酸的分析方法.结果表明,当肌氨酸浓度在0.5~350μmol/L范围内时,吸光度与其浓度呈良好的线性关系,方法的检出限为0.3μmol/L;将该方法应用于人体尿样的测定,回收率为94%~99%.
Water soluble carbon quantum dots(CQDs)were prepared from fruit skin.Transmission electron microscopy(TEM)analysis showed that the average particle size of the CQDs was 2.4 nm.Fourier transform infrared spectroscopy(FTIR)revealed that the surface of CQDs was predominated in oxygen-containing functional groups.The obtained CQDs could catalyze the H_(2)O_(2)-mediated oxidation of 3,3’,5,5’-tetramethylbenzidine(TMB)to produce the corresponding blue oxidized product(ox-TMB).Thus,a simple method for the detection of H_(2)O_(2) was established.Under the conditions of pH=3.5,temperature of 40℃,1.0 mmol/L TMB and incubation time of 15 min,the absorbance of ox-TMB increased linearly with the increase of H_(2)O_(2) concentration in the range of 5.0—100μmol/L,and the detection limit(3σ/k)for H_(2)O_(2) was 3.0μmol/L.Given the fact that H_(2)O_(2) was one of the products of sarcosine oxidase(SOX)-catalyzed sarcosine oxidation,a method for the indirect detection of sarcosine based on CQDs-catalyzed and H_(2)O_(2)-mediated TMB oxidation was also developed.The increase of ox-TMB absorbance enabled the sensitive determination of sarcosine in the range of 0.5—350μmol/L,and the detection limit sarcosine was calculated to be 0.3μmol/L.The method exhibited its potential application in the detection of sarcosine in human urine samples with the recovery of 94%—99%.
作者
舒馨
王迪
袁春玲
覃秀
王益林
SHU Xin;WANG Di;YUAN Chunling;QIN Xiu;WANG Yilin(School of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,China)
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2021年第6期1761-1767,共7页
Chemical Journal of Chinese Universities
基金
广西自然科学基金(批准号:2018GXNSFAA050015)资助。
关键词
碳量子点
模拟酶
比色法
Carbon quantum dot
Mimetic enzyme
Colorimetry
