Metal-Organic Framework as a Chemosensor Based on Luminescence Properties for Monitoring Cetyltrimethylammonium Bromide and Its Application in Smartphones.

Rapid and sensitive detection of surfactants has attracted more and more attention since surfactants not only cause water pollution but also affect the health of human beings. Luminescent metal-organic frameworks combining unique optical property and inherent permanent porosity for guest-host encapsulation are widely used in fluorescence detection. Here we report a ratiometric fluorescent probe (denoted as UiO-66-NH2@PB) based on a Zr-based metal-organic framework (UiO-66-NH2) and a fluorescent dye, phloxine B (PB), for visual and fluorescent determination of cationic surfactants (cetyltrimethylammonium bromide; CTAB). The intensity ratio of dual-emission sensor exhibits a linear response to the CTAB concentrations of 0.1-17 μM and obtains a low detection limit (0.074 μM). Moreover, this method has been successfully utilized to monitor CTAB in the environmental water samples with satisfied recoveries. Importantly, this work provides a new insight into developing smartphone-based sensor to realize a rapid, on-site visual and quantification-based detection of CTAB.