Thermo-responsive photoluminescent polymer brushes device as a platform for selective detection of Cr(vi)

Abstract

In this work, we first report a thermo-responsive photoluminescent polymer brushes device as a platform for the selective and sensitive detection of Cr(VI). Positively charged fluorescent molecules of a quaternary ammonium tetraphenylethylene derivative (d-TPE) are immobilized in the thermo-responsive polymer brushes of p(NIPAM-co-AAc) by Coulombic force, which leads to the observation of an immobilized induced emission (IIE) phenomenon. The emission intensity of the d-TPE labelled film is improved hundreds of times compared with a d-TPE aqueous solution. As a result, we obtain a novel thermo-responsive polymer brushes device with excellent photoluminescent properties. The photoluminescence (PL) intensity of the device exhibits a linear and reversible response from 4 to 60 °C and shows a high PL quenching for the sensitive and selective detection of Cr(VI) rather than Cr(III). The limit of detection can reach as low as 0.05 ppm, which indicates a promising sensor device for environmental monitoring, laboratory analysis and various other applications.