Enzyme‐Assisted Metal–Organic Framework Sensing System for Diethylstilbestrol Detection

Abstract

As novel fluorescent-sensing materials, metal-organic frameworks (MOFs) have shown great potential in environmental monitoring. However, most of the researches are limited to traditional pollutants, whereas the application of MOFs to the detection of the pollutants with more complicated structures, such as endocrine disrupting chemicals (EDCs), has rarely been explored. The difficulties faced in the sensing of EDCs include their electronic stability and the structural similarity among homologues, which could be overcome by the incorporation of enzymatic reaction. In this work, the first example of enzyme-assisted MOF-fluorescent-sensing was developed for the analysis of diethylstilbestrol (DES, a synthetic estrogen). In this system, DES is first oxidized by HRP/H O quantitatively to its quinone form, and then the quinone product is selectively captured by a stilbene based luminescent MOF to induce fluorescence response. By the tandem sensitization and filtration of enzymatic reaction and MOF adsorption, this method shows high sensitivity (DL=89 nm) and can distinguish DES from other similar-structured EDCs.

A stable zirconium based metal-organic framework for specific recognition of representative polychlorinated dibenzo-p-dioxin molecules

“…The invariant fluorescence lifetime is typical for a static quenching pathway 46 . In the static quenching mechanism, the sensor would form a non-fluorescent complex with the analyte in the ground state, and this pre-association determines the quenching efficiency 47–49 .…”

“…Therefore, to detect TCDD and BCDD by using fluorescent Zr-MOFs, the dynamic/static quenching seems to be the only mechanism. Generally, dynamic quenching occurs mainly when there is a collision between a guest molecule and the heteroatoms in the fluorescent host, and in the static quenching mechanism, the sensor would form a non-fluorescent complex with the analyte in the ground state, and this pre-association determines the quenching efficiency 37,47 . Interestingly, TCDD and BCDD are highly conjugated planar molecules and contain rich heteroatoms and H atoms, which are easily form weak interactions such as π–π stacking or hydrogen bonding with some conjugated systems.…”

A Green Blue LED-Driven Two-Liquid-Phase One-Pot Procedure for the Synthesis of Estrogen-Related Quinol Prodrugs

“…The mechanism of dye-mediated photo-oxygenation of phenols has been reviewed and discussed; it includes the transfer of the excited state from the photosensitizer to the substrate (Type I mechanism), or alternatively the inter-crossing system between the photosensitizer and dioxygen, with formation of singlet oxygen ( 1 O 2 ) (Type II mechanism) [38,[41][42][43]. Under our experimental conditions, the Type I mechanism was most probably not operating, as suggested by the loss of reactivity of the substrate in the absence of meso-TPP (Table 1, entry 5), associated with the low absorption coefficient of estrogens in the interaction with blue-LED photons (Figures S3-S6) [44][45][46][47]. Additional experiments were performed to investigate the possible involvement of the Type II mechanism [43,48].…”

Interaction between laccase and diethylstilbestrol based on multispectral and chromatography analyses

“…With increases in DES concentration, the fluorescence intensity of LAC gradually decreases; that is, fluorescence quenching occurs. Generally, dynamic quenching occurs mainly whenthere is a collision between a guest molecule and the heteroatoms in the fluorescent host, and in the static quenching mechanism, the sensor would form a non-fluorescent complex with the analyte in the ground state, and this pre-association determines the quenching efficiency 25,26. A distinction could be made between the two mechanisms according to the relationship between the quenching constant (K sv ) and temperature.…”