Cyanide detection using a benzimidazole derivative in aqueous media

• Receptor S1 shows highly sensitive fluorescence turn on response for CN−.
• Sensor S1 demonstrates specifically selective fluorescence recognition to CN−.
• Test strips of S1 were prepared and convenient and rapidly detected CN−.
• The probe S1 responded with CN− in aqueous solution system.
• Chemosensor S1 was designed with ease of synthesis.

A novel cyanide selective fluorescent chemosensor S1 based on benzimidazole group and naphthalene group as the fluorescence signal group had been designed and synthesized. The receptor could instantly detect CN− anion over other anions such as F−, Cl−, Br−, I−, AcO−, H2PO4−, HSO4−, SCN− and ClO4− by fluorescence spectroscopy changes in aqueous solution (H2O/DMSO, 8:2, v/v) with specific selectivity and high sensitivity. The fluorescence color of the solution containing sensor S1 induced a remarkable color change from pale blue to mazarine only after the addition of CN− in aqueous solution while other anions did not cause obvious color change. Moreover, further study demonstrates the detection limit on fluorescence response of the sensor to CN− is down to 8.8 × 10−8 M, which is far lower than the WHO guideline of 1.9 × 10−6 M. Test strips based on S1 were fabricated, which could act as a convenient and efficient CN− test kit to detect CN− in pure water for “in-the-field” measurement. Thus, the probe should be potential applications in an aqueous environment for the monitoring of cyanide.

A novel cyanide specifically selective and highly sensitive fluorescent enhanced chemosensor S1 based on benzimidazole group and naphthalene group was designed and synthesized.Figure optionsDownload as PowerPoint slide