A visible light excitable pyrene-naphthalene conjugate for ON fluorescence sensing of histidine in living cells

Pyrene appended naphthalene derivative, NEDAP can selectively detect histidine via inter-molecular H-bond assisted molecular ring formation that imparts rigidity to the molecular assembly to inhibit the TICT (Twisted Intra-molecular Charge Transfer) process leading to fluorescence enhancement. H-1 NMR titration, mass spectra and DFT (Density Functional Theory) studies nicely demonstrate this sensing process. Visible light excitation favours the living cell imaging as low as 0.01 mu M histidine.