Photoelectrochemical Detection of Glutathione by IrO2-Hemin-TiO2 Nanowire Arrays

We have developed sensitive detection of glutathione using the IrO2-hemin-TiO2 nanowire arrays. Single-crystalline TiO2 nanowires are synthesized by a hydrothermal reaction, followed by surface functionalization of similar to 3 nm thick hemin and similar to 1-2 nm diameter IrO2 nanoparticles. The IrO2-hernin-TiO2 nanowire arrays offer much enhanced photocurrent with similar to 100% increase compared to the pristine TiO2 nanowires and allow for label-free, real-time, sensitive photoelectrochemical detection of glutathione. The sensitivity achieved is similar to 10 nM in buffer, comparable to or better than most of the existing glutathione detection methods. Furthermore, cell extracts containing glutathione are robustly detected, with similar to 8000 cells/mL for HeLa cells and similar to 5000 cells/mL for human embryonic kidney 293T cells. This nanowire PEC sensor assay exhibits excellent selectivity and stability, suggesting a potential detection platform for analyzing the glutathione level in biosamples.