Imidazo[1,2‐a]pyridine Based D‐π‐A Fluorescent Sensor for Detection of Diethylcyanophosphonate

Abstract Herein, two fluorescent probes IM‐MN and IM‐ECA based on D‐π‐A system were synthesized, characterized, and evaluated for their photophysical properties. The probes were found to exhibit solvatochromic properties showing the range of fluorescence color in different polar solvents. The solvatochromism of the probes was further employed for DCNP detection. Both the probes showed excellent sensitivity and selectivity towards DCNP with fluorescence quenching response in the presence of DCNP, under UV lamp (365 nm). The probe IM‐ECA was found more sensitive in comparison to IM‐MN for detecting the presence of DCNP even at the nanomolar range. The SEM analysis has revealed the phenomenon of aggregation upon interaction of probe with DCNP that led to fluorescence quenching further, blue shift of the absorption band in UV spectra indicated formation of H‐ aggregates. Also, probes IM‐MN and IM‐ECA were fabricated into portable paper strips for real‐time detection that also resembles the response obtained in the solution phase.