Juan He,Xiaomin Xu,Hainan Sun,Tengfei Miao,Meisheng Li,Shouyong Zhou,Wei Zhou
The harmful effects on the human body from p-phenylenediamine (PPD) in hair dyes can cause allergies and even cancer. Therefore, it is particularly important to accurately control and detect the content of PPD in our daily products and environment. Here, a small amount of non-metallic elemental P doped in perovskite oxide of SrCoO3−δ(SC) forms a good catalytic material, SrCo0.95P0.05O3−δ(SCP), for PPD detection. The improved performance compared with that of the parent SC can be attributed to three contributing factors, including a larger amount of highly oxidative oxygen species O22−/O−, better electrical conductivity, and more active sites on the P5+-oxygen bonds of SCP. Moreover, the lattice oxygen mechanism (LOM) with highly active species of lattice O vacancies and adsorbed –OO for electrocatalytic oxidation of PPD by the SCP/GCE (glass carbon electrode) sensor is proposed in our work. More importantly, the SCP/GCE sensor exhibits good stability, a low limit of detection, and high reliability (error < 5.78%) towards PPD determination in real samples of hair dyes, suggesting the substantial research potential for practical applications.Keywords:lattice oxygen;phosphorus-doped SrCo0.95P0.05O3−δ;p-phenylenediamine (PPD);electrochemical sensors;hair dyes
Caixia Sun,Xue Zhang,Hao Huang,Ya Liu,Xianwei Mo,Yufei Feng,Jiahong Wang,Wenhua Zhou,Paul K. Chu,Xue-Feng Yu,Wenxin Liu
Nanozymes with enzyme-like characteristics have drawn wide interest but the catalytic activity and substrate selectivity of nanozymes still need improvement. Herein, Se-vacancy-rich TiSe 2-x @Au nanocomposites are designed and demonstrated as nanozymes. The TiSe 2-x @Au nanocomposites show excellent peroxidase-like activity and the chromogenic substrate p-phenylenediamine (PPD) can be selectively oxidized to compounds that exhibit an absorption peak at 413 nm that differs from that of self-oxidation or generally oxidized species, suggesting high catalytic activity and strong substrate selectivity. Theoretical calculations reveal that the PPD adsorption geometry at Se vacancies with an adsorption energy of −3.00 eV shows a unique spatial configuration and charge distribution , thereby inhibiting the free reaction and promoting both the activity and selectivity in PPD oxidation . The TiSe 2-x @Au colorimetric system exhibits a wide linear range of 0.015 mM–0.6 mM and a low detection limit of 0.0037 mM in the detection of glucose. The blood glucose detection performance for human serum samples is comparable to that of a commercial glucose meter in the hospital (relative standard deviation < 6%). Our findings demonstrate a new strategy for rapid and accurate detection of blood glucose and our results provide insights into the future design of nanozymes.
危险品化学品经营许可证（带存储）