摘要
以荔枝皮为原料制备碳量子点(CQDs),此CQDs具有类过氧化物酶活性,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,而半胱氨酸(CySH)能还原TMB的氧化产物(ox-TMB)使其褪色。基于上述原理,建立了以CQDs为类过氧化物酶的CySH测定方法。以TMB为底物,考察了pH值和温度等因素对CQDs催化性能的影响。实验结果表明,当TMB浓度为0.25 mmol/L时,在pH=3.5、反应温度40℃、反应时间10 min、 0.5 mmol/L H_2O_2及0.5μg/mL CQDs等条件下,体系吸光度的减少值(ΔA)与半胱氨酸浓度在0.05～4.00μmol/L范围内呈良好的线性关系,检出限为0.02μmol/L(3σ/k)。血清中的常见氨基酸不干扰测定,实际血清样品中半胱氨酸的加标回收率为94.0%～104.0%。
Carbon quantum dots(CQDs) were prepared from litchi rind. CQDs could catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine(TMB) in the presence of H2O2 to form oxidized TMB(ox-TMB) with an absorption peak at 652 nm. However, the introduction of cysteine(CySH) could cause the reduction of ox-TMB, resulting in a decrease of the absorbance at 652 nm. Based on this, a colorimetric method using CQDs as mimetic peroxidase was developed for determination of CySH. With TMB as a substrate, the effect of experiment conditions including pH of system and reaction temperature on catalytic activity of the obtained CQDs was studied. Under the optimal conditions, e.g. pH 3.5, reaction temperature of 40℃, reaction time of 10 min, 0.5 mmol/L H2O2, 0.5 μg/mL CQDs and 0.25 mmol/L TMB, the response was linearly proportional to the concentration of CySH in the range of 0.05-4.00 μmol/L with a detection limit of 0.02 μmol/L(3σ/k). The method proposed here exhibited excellent selectivity and common amino acids in serum did not interfere with detection of CySH. This method was successfully applied to determination of CySH in human serum sample with recoveries of 94.0%-104.0%.
作者
文辉忠
梁英彩
肖程月
邱子情
李娟
李妍妍
钟青梅
舒馨
王益林
WEN Hui-Zhong;LIANG Ying-Cai;XIAO Cheng-Yue;QIU Zi-Qing;LI Juan;LI Yan-Yan;ZHONG Qing-Mei;SHU Xin;WANG Yi-Lin(School of Chemistry and Chemical Engineering,Guangxi University,Guangxi Key Laboratory of Biorefinery,Nanning 530004,China)
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2019年第4期591-596,共6页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金项目(No.21661006)
广西生物炼制重点实验室开放基金(No.GXKLB-201801)
广西大学大学生创新创业训练计划项目(No.201810593040)资助~~
关键词
碳量子点
模拟酶
半胱氨酸
Carbon quantum dots
Mimetic enzyme
Cysteine
