Synthesis of orange emissive poly(o-phenylene diamine) nanoparticles and its application for solvents, pH and Ag+ sensing

Abstract

pH plays many essential functions in living organism while silver find applications in day to day life. However abnormal pH and improper dumping of silver ions can be lethal for living being. Herein, an orange emissive ploymer nanoparticles (OPNP) is synthesized by oxidative method at room temperature using 1, 2 diaminobenzene and potassium peroxodisulfate.The as obtained OPNP is characterized by TEM, FESEM, PXRD, FT-IR, EDX, UV–visible and fluorescence spectroscopy. The fluorescence of the obtained OPNP is highly sensitive to solvents, pH and Ag⁺ ions. The fluorescent color of the OPNP is tuned from orange to bluish green (560–485 nm) by adjusting the polarity of the solvents. The fluorescence intensity of OPNP increases as the pH is increased from acidic (pH-2) to basic medium (pH-12). The fluorescence of the OPNP is quenched by Ag⁺ ions, hence it is employed for selective detection of Ag⁺ ions both in solid and aqueous phase. The calibration plot for Ag⁺ is linear in the 0–30 μM concentration ranges and its limit of detection is 0.398 μM, which is lower than the permitted limit of WHO. Furthermore, the fluorescent OPNP is explore for determination of Ag⁺ ion in environmental samples with good recoveries ranging from 95.83 to 103 %.