The reference spectrum for mineral water is shown in Figure (A), the interference peaks near 1130 cm -1 are probably due to the interaction between Gum Arabic and chemicals present in mineral water. In the range of concentration from 0.15 nM to 1.5 µM, a linear calibration plot was obtained: y = 0.5865 + 0.0329*log10(x), where x is the peak ratio I1130 cm-1 / I1400 cm-1, with a R 2 = 0.9804. Similar results were obtained for river water, see Figure (B) again in the concentration range of 0.015 nM to 1.5 µM. A linear calibration plot of y = 0.6456 + 0.0180*log10(x), with R 2 = 0.9681 was obtained. A direct comparison of the sensor developed herein with those reported in the literature is provided in SI Table and Table , as can be seen the senor performance in detection limit is better than previously reported SERS platforms and better than high-end laboratory based HPLC-MS instrumentation or other platforms .