An ultrasensitive electrochemiluminescence aptasensor for the detection of diethylstilbestrol based on the enhancing mechanism of the metal–organic framework NH2-MIL-125(Ti) in a 3,4,9,10-perylenetetracarboxylic acid/K2S2O8 system

Abstract

In this work, a sensitive and selective electrochemiluminescent aptasensor was proposed based on the enhancing mechanism of the metal–organic framework NH₂-MIL-125(Ti) in a 3,4,9,10-perylenetetracarboxylic acid/K₂S₂O₈ system for a diethylstilbestrol assay. Herein, 3,4,9,10-perylenetetracarboxylic acid was selected as the major luminophore, and the metal–organic framework NH₂-MIL-125(Ti) displayed a large specific surface area to immobilize abundant PTCA molecules to facilitate electrochemiluminescence efficiency. Besides, the metal–organic framework NH₂-MIL-125(Ti) was used as a novel catalyst in the 3,4,9,10-perylenetetracarboxylic acid/K₂S₂O₈ system, which could react with the co-reactant K₂S₂O₈ to produce more SO₄˙⁻. In addition, we introduced the amino-aptamer of diethylstilbestrol; due to the specific binding affinity between the aptamer and diethylstilbestrol, a selective electrochemiluminescent aptasensor for diethylstilbestrol was thus developed here. Under the optimal conditions, a wide detection range from 1.0 fM to 1.0 μM with a low detection limit of 0.28 fM (S/N = 3) was obtained. More importantly, the residual diethylstilbestrol in water was detected by the developed aptasensor; this confirmed that this method has good performance and potential applications in real samples.