A biomimetic sensor for the determination of extracellular O-2(-) using synthesized Mn-TPAA on TiO2 nanoneedle film

作者：Luo, Yongping; Hu, Guoqi; Zhu, Anwei; Kong, Biao; Wang, Zhen; Liu, Chunyuan; Tian, Yang^*

来源：Biosensors and Bioelectronics, 2011, 29(1): 189-194.

DOI：10.1016/j.bios.2011.08.017

• Biomimetic sensor
• Superoxide ion
• Mn-TPAA
• TiO2 nanoneedles
• Living cells

By immobilizing synthesized Mn-TPAA (TPAA = tris[2-[N-(2-pyridylmethyl) amino] ethyl] amine) on TiO2 nanoneedle surface, a biosensor for superoxide ion (O-2(-)) has been developed and applied for determination of O-2(-) released from living cells. Direct electron transfer of Mn-TPAA is realized with a formal redox potential (E degrees') falling in the range of the E degrees' values of the redox couples O-2/O-2(-) and O-2-/H2O2. This suggests that Mn-TPAA on TiO2 films is electrochemically active and capable of thermodynamically mediating both the oxidation of O-2(-) to O-2 and the reduction of O-2(-) to H2O2. Therefore, Mn-TPAA immobilized on the TiO2 films can be used electrochemically for determination of O-2(-) due to its electrochemical activities and biomimetic catalytic activities like superoxide dismutase (SOD) toward O-2(-). The present biomimetic O-2(-) sensor shows high selectivity at the low working potential of 0 V vs. Ag|AgCl, a wide linear range from 10(-7) M to 10(-4) M and a quick response time within 6s. By taking advantage of the developed method and the properties of biomimetic SOD themselves, we have realized the real-time monitoring of O-2(-) concentration released from living cells and investigated the relationship between the concentration changes of O-2(-) and intracelluar Ca2+, which may gain additional insights on the reactive oxygen species (ROS) signal transduction and other physiological and pathological events.

• 出版日期2011-11-15
• 单位同济大学