Carcinogenic chromium (VI) sensing using swelling characteristics of hydrogel on Fiber Bragg grating

The present article proposes carcinogenic Chromium (VI) metal ion sensor by a hydrogel coated etched Fiber Bragg grating (FBG). Hydrogel synthesized from the blends of 3-arylamidopropyltrimethylammoniumchloride (ATAC) which is stimulus responsive to chromium ions suffers a volume change in different Cr solutions. Upon exposure to various concentrations of Cr (VI) ion solutions, FBG peak is shifted due to the mechanical strain induced by the stimulus swelling property of the hydrogel. The peak shift is correlated with the concentration of the Cr (VI) metal ion. Thus a Chemo-mechanical- optical sensing approach for the detection of Cr (VI) is studied. Trace amounts of Chromium (VI) ion as low as 10 ppb can be estimated by the method. The resolution of the sensor system is found to be 0.05 ppb.