A novel colormetric and light-up fluorescent sensor from flavonol derivative grafted cellulose for rapid and sensitive detection of Hg2+ and its applications in biological and environmental system

Abstract

Mercury ion (Hg²⁺) is one of harmful heavy metal ions that can accumulate inside the human organism and cause some health problems. In the article, a highly effective fluorescent probe named EC-T-PCBM was prepared by grafting flavonol derivatives onto ethyl cellulose for the specific recognition of Hg²⁺. EC-T-PCBM exhibited a remarkable fluorescence light-up response toward Hg²⁺ with excellent sensitivity. EC-T-PCBM possessed several prominent sensing properties for Hg²⁺, such as low detection limit (43.9 nM), short response time (5 min), and wide detection pH range (6-9). The response mechanism of EC-T-PCBM to Hg²⁺ has been verified through ¹H NMR titration and DFT computation. Additionally, EC-T-PCBM not only can be used for accurately determining trace amount of Hg²⁺ in actual environmental water samples, but also can serve as a portable and rapid device by loading it on test strips for sensitive and selective visualization of Hg²⁺. More importantly, the confocal fluorescence imaging of onion cells suggested the favorable cell membrane permeability of EC-T-PCBM and its prominent ability to continuously monitor the enrichment from Hg²⁺ within fresh plant tissues.

Keywords: Ethyl cellulose; Fluorescent probe; Hg(2+) ion.