Abstract
By immobilizing synthesized Mn-TPAA (TPAA=tris[2-[N-(2-pyridylmethyl) amino] ethyl] amine) on TiO 2 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°') falling in the range of the E°' values of the redox couples O 2/O 2 - and O 2 -/H 2O 2. This suggests that Mn-TPAA on TiO 2 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 H 2O 2. Therefore, Mn-TPAA immobilized on the TiO 2 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 0V vs. Ag|AgCl, a wide linear range from 10 -7M to 10 -4M 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 Ca 2+, which may gain additional insights on the reactive oxygen species (ROS) signal transduction and other physiological and pathological events.
| Original language | English |
|---|---|
| Pages (from-to) | 189-194 |
| Number of pages | 6 |
| Journal | Biosensors and Bioelectronics |
| Volume | 29 |
| Issue number | 1 |
| DOIs | |
| State | Published - 15 Nov 2011 |
| Externally published | Yes |
Keywords
- Biomimetic sensor
- Living cells
- Mn-TPAA
- Superoxide ion
- TiO nanoneedles