A fluorescent nanoprobe and paper-based nanofiber platform for detection and imaging of Fe3+ in actual samples and living cells

In this study, a novel fluorescent nanoprobe (ZIF-90@FSS) was constructed using a zeolite imidazolium ester skeleton (ZIF-90) incorporating sodium fluorescein within its porous structure. Notably, this nanoprobe exhibited regular fluorescence “off” detection performance of Fe3+ in actual samples and living cells. The concentration range of 0–150 ng/mL exhibited a lowest detection limit of 0.26 ng/mL. A nanofiber paper-based platform (VL78/ZIF-90@FSS) was further developed by coupling the prepared nanoprobe to a multi-dimensional fiber paper via CN bonds, enabling rapid visual white light colorimetric and fluorescence imaging of Fe3+ within 2 min. The constructed nanoprobe and its paper-based detection platforms demonstrated a stable recovery range in tap water, beer, and soy sauce samples during spiking-recovery assessments. The recovery rates ranged from 98.46 % to 108.24 % for the nanoprobe and from 91.75 % to 108.71 % for the nanofiber paper-based platform. Therefore, the developed nano-fluorescent sensor and paper-based nanofiber sensing platform offer a promising strategy for the visual detection of Fe3+, while also presenting novel and valuable methods to investigate the regulatory mechanisms of Fe3+ in living cells. [Display omitted] •A novel fluorescent nanoprobe ZIF-90@FSS and paper-based nanofiber platform VL78/ZIF-90@FSS were developed.•ZIF-90@FSS and VL78/ZIF-90@FSS exhibit dynamic sensing and real-time imaging of Fe3+ in living cells and actual samples.•ZIF-90@FSS achieved fluorescence "off" detection of Fe3+ based on fluorescence energy transfer and absorption competition.•The ZIF-90@FSS nanoprobe exhibited rapid detection in vitro and spatiotemporal resolution for Fe3+ imaging in vivo.