Fig. 6: Selectivity performance of the Pb2+ ion photonic sensor against.
From: Crown ether decorated silicon photonics for safeguarding against lead poisoning

a Cd2+, and b, K+ at reference concentrations of 15 ppb in DI water where no shifts in the interferometric spectra indicative of ion binding is observed. c The detection performance of the Pb2+ photonic ion sensor is evaluated at reference Pb2+ concentrations of 15 ppb in DI water. The pH of the analyte is maintained at 6.8 (see Methods).