High Photoluminescence Polyindole/CuInS Quantum Dots for Pb Ions Sensor

Abstract Polyindole is considered an excellent conducting polymer with interested properties for different applications. A novel polyindole (PIn)/CuInS (CIS)/ZnS quantum dots (QDs) nanocomposite was synthesized via in situ polymerization of PIn presence CIS/ZnS QDs. By investigating the effect QDs on optical PIn, it found that band gaps QDs, and PIn/CIS/ZnS were 3.24 eV, 4.68 eV 3.44 respectively. From luminance spectra, observed emission peaks at 442 468 nm are independent excitation wavelength highest intensity 380 nm. However, spectrum exhibited a quenching peak while enhanced. High resolution transmission electron microscope image revealed nanocrystals size 3–4.5 lattice space 0.2 as fluorescent probe employed sensing concentrations Pb 2+ from 5 to 50 ppb. The reaction between slightly quenched fixed after 90 min. reduced gradually increasing concentration lead photo-induced transfer or ion exchange mechanism. value correlation coefficient (R 2 ) 0.99, sensitivity 0.0041 ppb −1 limit detection 4.48