Thiophene-derived “off-on-off” fluorescence chemosensors for the detection of zinc and phytate ions sequentially

In this study, thiophene-based small molecule sensors R and Q were designed and synthesized, which could monitor Zn2+ and phytate ions sequentially in aqueous solution according to “off-on-off” fluorescence. Both sensors exhibited ultrasensitive response to target ions over other reported sensors, especially toward phytate ions, with the low detection limits (3.04 × 10−10 M) and fast detection rates (<10 s). More importantly, the ethylenedioxy-modified complex Q-Zn2+ showed super selectivity for phytate ions than PPi and PO43−, without the need for pretreatment of the tested solution, which was currently an excellent fluorescence platform for the detection of phytate ions. The recognition process of target ions was explained in detail through spectral measurement and MS spectrum titration. Furthermore, the theoretical calculations were performed to provide reasonable evidence for excellent behavior of sensors. Moreover, the quantitative detection of Zn2+ and phytate ions in water samples supported strongly for application potential of both sensors.