Selective sensing of copper (II) and leucine using fluorescent turn on – off mechanism from calix[4]resorcinarene modified gold nanoparticles

Abstract In this paper, octa- O -methoxy resorcin[4]arene tetrahydrazide (OMRTH) have been used as reducing as well as stabilizing agent for the preparation of gold nanoparticles via simple one pot method. Synthesized gold nanoparticles (OMRTH-AuNps) were characterized by UV–vis spectroscopy, Transmission Electron Microscopy (TEM) and Particle Size Analyzer (PSA). In addition, the interaction of different cations like Ag + , Pb 2+ , Cu 2+, Fe 2+ , Hg 2+ , Ni 2+ and amino acids like Arginine, Cysteine, Aspartic Acid, Glutamic Acid, Glutamine, Leucine, Methionine, Thryonine, Tryptophan with synthesized gold nanoparticles have been studied by UV–vis and fluorescence spectroscopy. Using OMRTH-AuNps as a selective and sensitive fluorescent probe, Cu 2+ ions could be detected at a minimum concentration level of 10 μM in a facile way of fluorescence quenching i.e. by a “turn off” mechanism. Furthermore, reversible simultaneous fluorescence recovery was also observed when leucine was added in the same solution, which shows the “On-Off” mechanism of OMRTH- AuNPs. Further, the Write-Read-Erase-Read” function of the memory element was evaluated for three input combinations chemical inputs ( In Cu and In Leu) are integrated through a series of Set/Reset operations involving logic operations to produce an information processing device.