DEVELOPMENT OF H2O2 IMAGE SENSOR FOR GABA AND GLUTAMATE IMAGING

We have developed H2O2 image sensors of 128x128 pixels with spatial resolution of 23.55 mu m successfully. This sensor consisted of hexacyanoferrate(II), hexacyanoferrate(III), enzyme, and an Au thin film deposited on a highly sensitive potential image sensor, where hexacyanoferrate(II), hexacyanoferrate(III), and enzyme were immobilized on the Au film. The H2O2 image sensor measures the interfacial potential between the solution and the Au film caused by a redox reaction involving H2O2, and thus the sensor signal is not affected by the buffering action of the solution. The output increased linearly with the ratio of Fe2+, Fe3+ of their mixture; thus it was confirmed that the sensor can measure the redox potential qualitatively. Furthermore, we demonstrated that the sensor can visualize the diffusion behavior of H2O2 and glutamate. These results also suggest the possibility of imaging neurotransmitters such as Serotonin, Dopamine etc, by utilizing the enzyme reaction that generates H2O2.