DPP based dual-sensing probe for the multi-color detection of toxic Co2+/ Sn2+and CN- ions in water: An electronic eye development

A dual-sensing mechanism probe for the multi-color detection of toxic Co2+/Sn2+ and CN- ions in water based on a diketopyrrolopyrrole (DPP) moiety was designed and successfully synthesized. Colorimetric and fluorimetric methods were used to confirm the sensing performance of the probe. Different colors were achieved for the detecting ions Co2+, Sn2+, and CN-. pink for Co2+, red for Sn2+, and colorless for CN-, denoting high selectivity in the developed probe. A dual-sensing mechanism confirmed for the metal ion the sensing is via complexation resulting in color (different) change through metal to ligand charge-transfer transition (MLCT), and for anion (cyanide), it is through addition reaction with a disconnection in intramolecular charge-transfer transition (ICT). Pre-added selected ions to the different water samples effectively detect different colors. We developed an electronic eye (RGB - Arduino device) for the detection of toxic ions effectively.