Di-(2-picolyl)amine functionalized tetraphenylethylene as multifunctional chemosensor

Abstract

In this study, we successfully developed a new multifunctional chemosensor 4′,4‴-(2,2-diphenylethene-1,1-diyl)bis(N,N-bis (pyridin-2-ylmethyl)-[1,1′-biphenyl]-4-amine (T-D), based on the cooperation of tetraphenylethylene and di-(2-picolyl)amine (DPA), for sensitive, selective, and quick detection of Cu2+, PO43− and pesticide glyphosate in aqueous solution. In our research, we made full use of the Cu2+-indicator displacement strategy to achieve the construction of an “on-off-on” fluorescent switch platform. Due to the presence of the DPA moiety in T-D, Cu2+ could be captured quickly to form the complex T-D-Cu and caused fluorescence quenching. With the addition of PO43− and glyphosate, the system could rapidly restore the fluorescence by squeezing Cu2+ from T-D-Cu and blocking the photo induced electron transfer (PET) process to display the aggregation-induced emission. To demonstrate the possibility of practical applications, we detected PO43− and glyphosate in spiked real samples. The detection limit for PO43− and glyphosate reached 19 nM and 25 nM, respectively. Furthermore, test strips using T-D-Cu solution simplified the detection process of glyphosate. More importantly, the sensor could be used in visual semi-quantitative determination of PO43− concentrations in both living cells and living zebra fish. Therefore, the chemosensor presented here will not only be a powerful tool for the detection of phosphate anions in aqueous solution and biological systems, but also provides a new template for the design of other multifunctional chemosensors.