Analytical Application Study Of Catalytic Active Nano/Micromaterials

In this paper, the inherent catalytic property of nano/micro-materials was used to build a series of colorimetric sensors. The main works as follows:1. Here, we found that Hg2+ can induce the synthesis of Au nanoparticles and the Au nanoparticles can catalyze the Au+-mediated oxidation of 3,3’,5,5’-tetramethylbenzidine (TMB) to generate blue oxidation state of TMB product. In the presence of Au+, TMB is hard to be oxidized. However, colorless reaction solution becomes blue quickly with add of Hg2+. Based on this finding, we successfully built a simple and rapid detection method for Hg2+. This method has advantages of high sensitivity and selectivity with a detection limit of 2 nM. That is much lower than The World Health Organization (WHO) standard for the maximum allowable level of inorganic mercury in drinking water which is no more than 6 ppb (30 nM)). This method is simple and fast without any complicated step and has been successfully applied to the detection of Hg2+ in real water sample.2. For the first time, we show that boron- and nitrogen-codoped carbon nano/microspheres (CNBs) has inherent peroxidase-like catalytic activity. And then we discuss the influence factors about carbonization temperature on CNBs and compare the catalytic activity between nitrogen-doped carbon nano/microspheres and CNBs. In the presence of hydrogen peroxide, CNBs can catalyze TMB to produce blue oxidation state of TMB product. Based on this phenomenon, CNBs can be applied to establish artificial mimic-enzyme system to detect hydrogen peroxide. We also applied it to detect glucose by combining with glucose oxidase. We show that CNBs has advantages of good stability, high catalytic efficiency, easy synthesis and low cost. So it is a promising approach to apply it to construct colorimetric sensor for hydrogen peroxide and glucose in real sample.