Preparation a novel phenylcarbazole-based fluorescent sensor for the sensitive and selective detection of CN− in water

•A novel phenylcarbazole-based fluorescent molecule (CPHB) is synthesized.•The CPHB sensor exhibited a remarkable sensing performance with low LOD at 2.49 × 10−7 mol·L−1.•The CPHB sensor shows good advantages on selectivity and anti-interference.•The fluorescent mechanism is belonged to ICT effect.