Figure 2 (IMAGE) Kanazawa University Caption (a) Surface enhanced Raman spectroscopy was used to detect and quantify the H<sub>2</sub>O<sub>2</sub>-induced modification of 4MPBE molecules assembled on the gold surface of the nanosensor anchored to the cells. The intensity of the Raman band at 998 cm-1 depends on H<sub>2</sub>O<sub>2</sub> concentration, while the band at 1074 cm-1 did not show modification and it can be used for normalization of the spectral lines. (b) Results of the nanosensor calibration. The ratio of the intensity at 1074 cm-1 to the intensity at 998 cm-1 showed linear dependence with respect to H<sub>2</sub>O<sub>2</sub> concentration. (c) Example of SERS hyperspectral map of extracellular endogenous H<sub>2</sub>O<sub>2</sub> collected from the surface of the A549 cell shown in the bright-field image. The SERS spectra shown in (a) were collected from the locations A and B. Credit Kanazawa University Usage Restrictions The image may only be used with appropriate caption and credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.