Imine-Linked electrochemical sensor for selective detection of HSO4− ions in aqueous media

Abstract

Imine linked dipodal organic receptor R1 has been synthesized and well characterized using different spectroscopic techniques such as 1 HNMR, 13CNMR and mass spectroscopy. R1 showed interesting potential for anion recognition. Its sensing ability has been evaluated by processing R1 into organic nanoparticles (ONPs). ONPs of R1 were developed using reprecipitation method. ONPs were first characterized using Dynamic light scattering (DLS) to estimate average size distribution of particles and then confirmed from Transmission electron microscopy (TEM). Further, ONPs were examined for their electrochemical behaviour using cyclic voltammetry and differential pulse voltammetry particularly in aqueous medium. ONPs were evaluated for binding test with various tetra butyl ammonium salts of anion and found to be selective towards HSO4 ions. Detection limit was found to be 8.2nM and regression coefficient equal to 0.982. ONPs behave selectively towards HSO4 ions even in the presence of competitive anions. Optical properties of ONPs were also examined. UVVisible and Fluorescence spectrophotometer showed significant change when TBA HSO4 ions were added to it. Prepared sensor was incorported for real sample containing HSO4 ions and results showed accuracy as high as 95%