Optimization of Molecularly Imprinted Polymer Method for Rapid Screening of 17β-Estradiol in Water by Fluorescence Quenching

Abstract EN

A new method was optimized for rapid screening of 17β-estradiol (E2) in water under 10 min.

Molecularly imprinted polymer (MIP) particles (325 ± 25 nm) were added in a water sample at pH 5.5 and 20∘C to form a suspension.

Fluorescence emission from E2 nonspecifically bound onto the MIP particles was first quenched by large gold nanoparticles (43 ± 5 nm).

The Stern-Volmer plot was linear, with dynamic quenching constants (Ksv) of 2.9 ×104 M-1.

Fluorescence emission from E2 specifically bound inside the MIP particles was next quenched by small nitrite anions that easily penetrated the imprinted cavities.

The Stern-Volmer plot became nonlinear, with Ksv = 2.1 × 102 M-1 and static quenching constant (V) below 1.0 M-1.

The difference between these two emission intensities varied as the initial E2 concentration in water, generating a Scatchard calibration curve with R2>0.97 from 0.1 to 10 ppb.