Pyranopyrazole based Schiff base for rapid colorimetric detection of arginine in aqueous and real samples

A novel pyranopyrazole-based Schiff base PPS has been synthesized via a condensation reaction between aldehyde and hydrazide derivatives of pyranopyrazole. The probe acted as a selective and sensitive chemosensor for the colorimetric detection of arginine under aqueous conditions with a detection limit of 1.8 × 10^-5 M. The 1 : 1 binding stoichiometry was established using various UV-vis spectroscopic methods. A plausible binding mechanism of PPS towards arginine was established via ¹H NMR titration techniques and the results were further validated using DFT studies. Moreover, PPS provided a reasonable response for arginine in dietary supplements and human blood plasma which demonstrates its potential application in real sample analysis as well.