基于碳酸锰纳米氧化酶活性调控比色检测谷胱甘肽

Colorimetric detection of glutathione through tuning the oxidase-like activity of MnCO_(3) nanoparticles

纳米氧化酶是一类具有类似天然氧化酶催化特性的纳米材料.调控纳米氧化酶的催化活性在生物传感和临床诊疗等应用领域具有重要意义.本文通过一步水热法制备了具有高效类氧化酶活性的碳酸锰纳米颗粒(MnCO_(3) NPs),其能够快速催化溶解氧产生活性氧自由基,从而催化氧化无色底物3,3′,5,5′-四甲基联苯胺(TMB)发生显色反应,其蓝色氧化态产物(oxTMB)在652 nm波长处展现出特征吸收峰.进一步研究发现,在该显色体系中加入谷胱甘肽(GSH)后MnCO_(3) NPs催化氧化TMB的反应受到抑制,蓝色产物oxTMB的生成减少,652 nm处的吸光度减弱且与GSH的浓度在一定范围内呈线性关系.基于该原理,本文构建了一种基于MnCO_(3) NPs类氧化酶活性调控比色检测GSH的新方法,并成功将其用于血清中GSH含量的测定.借助智能手机的拍照和色度分析功能,本文还开发了一种利用智能手机作为检测终端的便携式分析方法用于GSH的检测,该方法有望进一步扩展到床边检测与疾病诊断.

Nano-oxidases are a kind of nanomaterials with catalytic properties similar to natural oxidases.Regulating the catalytic activity of oxidase-like mimics is of great significance in biosensing as well as clinical diagnosis and treatment.In this article,MnCO_(3) nanoparticles(NPs)with oxidase-like activity were prepared by one-pot hydrothermal method,and were able to catalyze the production of reactive oxygen species from dissolved oxygen and transform colorless substrate 3,3′,5,5′-tetramethylbenzidine(TMB)into blue oxTMB with a characteristic absorption peak at 652 nm.Further studies showed that the catalytic oxidation of TMB by MnCO_(3) NPs could be inhibited by the addition of glutathione(GSH),and thus the production of oxTMB as well as the absorbance at 652 nm decreased,which showed a linear relationship with the concentration of GSH in a certain range.Based on this mechanism,a new colorimetric method for GSH detection based on regulating the oxidase-like activity of MnCO_(3) NPs was established and successfully applied to the determination of GSH in serum.With the assistance of smartphone,a portable analysis method for GSH detection was also developed with the application potential for point-of-care testing and disease diagnosis.