Ultrasensitive multiplexed immunosensors for the simultaneous determination of endocrine disrupting compounds using Pt@SBA-15 as a non-enzymatic label

Abstract

The simultaneous determination of different analytes based on multiplexed immunosensors is attractive and promising in bioassays and environmental analysis. In this paper, a novel ultrasensitive multiplexed immunoassay method was developed for the determination of endocrine disrupting compounds (EDCs) based on disposable screen-printed carbon electrodes. Different capture antibodies were separately immobilized on the carbon electrodes to form an immunosensor array. Platinum nanoparticle-functionalized mesoporous silica nanoparticles (Pt@SBA-15) was used as catalytic labels of secondary antibodies. Due to the catalytic activities of the platinum nanoparticles and the large surface area of SBA-15, a strong electrical response towards the analytical antigens was achieved. The multiplexed immunoassay array enables the simultaneous determination of different analytes. Using diethylstilbestrol and estradiol as model analytes, this multiplexed immunoassay method showed wide linear ranges with detection limits down to 0.28 and 1.2 pg mL⁻¹ for diethylstilbestrol and estradiol, respectively. The proposed sensing strategy enriches electrochemical immunoassays and has a promising application in bioassays and environmental analysis.