Dendritic Fibrous Nanosilica Hybrid Materials with Near-Infrared Emission as Multifunctional Sensors for Toxic Pollutants

摘要

Two dendritic fibrous nanosilica (DFNS)-based hybrid materials (DFNS-PDI-NR and DFNS-MDI-NR) with superior near-infrared (NIR) emission are developed. Based on the J-aggregate of neutral red (NR) modified on the surfaces of DFNS, the hybrid materials possess a narrow redshifted emission band at 866 nm compared with the monomeric NR dyes upon excitation in the visible region (575 nm). Significantly, integrating the robust support of DFNS and unique fluorescence properties of the aggregated NR dyes, DFNS-PDI-NR and DFNS-MDI-NR can serve as a novel type of multifunctional solid-state chemosensors for the detection of various toxic pollutants including transition-metal anions (Cr(2)O(7)(2-)and MnO4-), nitrophenols, and acetone with turn-off NIR-fluorescence signals. The quenching phenomena of DFNS-PDI-NR and DFNS-MDI-NR toward various toxic pollutants are established by nonlinear bend upward Stern-Volmer fitting. Moreover, these materials can be further used as sensitive probe materials for the determination of Cr2O72- and MnO(4)(-)levels in various real water samples.