Reactive Detection of Hydrazine by 6‐Hydroxy‐2‐Naphthonitrile Levulinate Anchored Colorimetric and Fluorescent Probe

Abstract Herein, a new reaction‐based fluorescent probe 6‐cyanonaphthalen‐2‐yl 4‐oxopentanoate (NPCN‐OLV) was designed and synthesized for the detection of hydrazine (N 2 H 4 ). The addition of N 2 H 4 to a solution of probe NPCN‐OLV resulted in a striking fluorescence increase, moreover, it is complemented by a visual color change from colorless to yellow. Importantly, this distinct color response indicates that probe NPCN‐OLV could be implemented as a colorimetric tool for the recognition of N 2 H 4 . N 2 H 4 can be detected quantitatively. The lower detection limit for the N 2 H 4 is 5 μM where actual fluorescence observed and gradually increased with concentration. The probe NPCN‐OLV served the selective visible naked‐eye sensing of hydrazine in the presence of representative metal ions and common anions. Along with that we have also demonstrated the use of paper strip for the qualitative detection of hydrazine, which showed an evident color change (sky blue) only with the paper strip with hydrazine in PBS buffer.