摘要
在酸性2-吗啉乙磺酸介质中，建立基于纳米金表面等离子体的微量过氧化氢（H2O2）的比色检测体系，探讨裸眼检测途径下的分辨极限，提高体系稳定性并利用光谱分析精确定量H2O2浓度（c）．结果表明，当c〈100μmol／L时，纳米金为团聚态，呈现蓝色；c〉120μmol／L时，纳米金为分散态，呈现红色．该方法的裸眼检测极限可分辨浓度差为20μmol／L．反应溶液的显色结果并不稳定，在反应后45min内变化较快，c为60—100μmoL／L的反应溶液也将逐渐由蓝色变为红色．溶液在570nm处的吸光度（OD570）检测证明，反应体系在检测后3h内仍持续变化．反应10min后，加入适量半胱甘肽终止反应，可使反应溶液的显色结果稳定，提高体系稳定性．实验测定不同浓度H2O2反应产物的吸收光谱发现，C〈100μmol／L的反应孔产物在波长约550nm处有吸收峰，且吸收强度与c成正相关．而c〉120μmol／L的反应产物吸收峰逐渐往短波长方向偏移，最终峰值约为540nm．分析反应体系吸收光谱结果证明，各反应产物在630nm和545nm处吸光度的比值（OD630/545）与c呈良好的线性关系．实验对c为100—120μmol／L的H2O2溶液进行检测，定量浓度差为2μmol／L的H2O2溶液，降低裸眼检测途径下该方法的分辨极限，为微量样品检测提供更好的平台．
A colorimetric method was developed for the determination of trace amount of H2O2 in acidic 2-（ N-mor- pholino） ethanesulphonic acid buffer medium, based on surface plasma of gold nanoparticles. The detecting system, whose limit of detecting resolution with naked eyes was measured previously, was used to accurately quantify the concentration （c） of H2O2 by spectral analysis after stabilization enhancement. The results show that blue-coloured solutions with aggregated gold nanopartictes could be obtained when c 〈 100 p, mol/L, while the solutions were red-coloured with non-aggregated gold nanoparticles when c 〉 120 μmol/L. The resolution limit of human eyes to this detection system was able to distinguish H2O2 concentration difference of 20 μmol/L. However, the color distinction of solutions was unstable and has a quick change in 45 rains. The blue solution with c of 60 to 100 μmol/L turned red gradually. The OD570 of solutions also demonstrates that the reaction was constantly changing in 3 h after detection. Moderate L-glutathione was added to terminate the reaction after 10 min to improve the detection stability, which can stabilize the color distinction and effectively keep a constant OD570. The spectra of the nanoparticle dispersions show the absorption peak at 550 nm and there is a positive correlation between intensity and the H2O2 concentration when c 〈 100μmol/L. The absorption peak shifted to 540 nm when c 〉 120 μmol/L. By the spectral analysis, a linear relativity of regressive curves of OD630/545 and the concentration of H2O2 was found. Then solutions with c from 100 to 120μmol/L were detected and accurately quantified H2O2 with concentration difference of 2μmol/L to break the limit of detecting resolution. The detection system could provide a preferential platform for trace detection.
出处
《华南师范大学学报（自然科学版）》
CAS
北大核心
2015年第4期41-45,共5页
Journal of South China Normal University(Natural Science Edition)
基金
国家自然科学基金项目(61405062)
广东省自然科学基金项目(S2013040014211
2014A030313445)
关键词
纳米金
过氧化氢
裸眼检测
gold nanoparticles
hydrogen peroxide
detection with naked eye
