A reliable fluorescent aptasensor for selective detection of trace estradiol based on metal–organic framework click-grafting aptamers functionalized fabric

Abstract

The presence of trace levels of 17β-estradiol (E2) in food and the environment presents a risk to human health, underscoring the need for the development of sensitive analytical methods to detect and accurately monitor its concentration. In this work, we designed a competitive-type fluorescent aptasensor combined with a novel PVDF@UiO-cDNA electrospun nanofiber for E2 detection. The FAM-labelled aptamer in the samples was partially hybridized with cDNA on the PVDF@PDA electrospun by the alkenylation UiO-66. Upon the presence of E2 in the samples, E2 target selectively binds to aptamer, effectively inhibiting its pairing with the cDNA. This innovative approach seamlessly integrated the high capacity electrospun nanofiber, readily modifiable MOF crystals, and the high specificity of aptamer, resulting in an enhanced response to the E2 target. Under the optimized conditions, the fluorescent aptasensor exhibited a wide linear range of 1–100 nM for E2, achieving a high coefficient of determination (R²) of 0.9929, and a low detection limit (LOD) of 0.33 nM. The stability and reproducibility of electrospun nanofiber were validated through its application to milk and water samples, with recoveries ranging from 96.9 % to 130.2 % and a relative standard deviation (RSD) below 8.1 %. These findings highlight the sensitivity and reliability of the developed aptasensor, demonstrating its potential for monitoring trace E2 levels in food and water environments.