An electrochemiluminescence sensor for ultrasensitive detection of Hg<SUP>2 </SUP> based on self-enhanced Ru-QDs@SiO<sub>2</sub> luminophore and P6ICA/MoS<sub>2</sub> as co-reaction accelerator

Key Words:RATIOMETRIC FLUORESCENCE SENSOR; RESONANCE ENERGY-TRANSFER; SENSITIVE DETECTION; QUANTUM DOTS; COLORIMETRIC DETECTION; LABEL-FREE; MERCURY; BIOSENSOR; COMPLEX; SAMPLES

Abstract:An electrochemiluminescence (ECL) biosensor combined with DNA signal amplification technology was constructed for Hg2 detection based on an efficient self-enhanced ECL luminophore (Ru-QDs@SiO2) and a novel co-reaction accelerator poly(indole-6-carboxylic acid)/molybdenum disulfide (P6ICA/MoS2). The Ru-QDs@SiO2 nanosphere was prepared by co-encapsulating the donor CdS QDs and acceptor Ru(bpy)(3)(2 ) into a silica nanoparticle, which enabled ECL resonance energy transfer (ECL-RET) to occur inside the Ru-QDs@SiO2 nanospheres, thereby shortening the electron transfer path between donor and acceptor, further enhancing the ECL signal intensity. Additionally, P6ICA/MoS2 was used as a novel co-reaction accelerator for the detection of Hg2 . P6ICA/MoS2 exhibits excellent conductivity and a well-defined hierarchical structure, making it to effectively facilitate the generation of more co-reactive free radicals, and provide a good substrate for fixing abundant cDNA. Meanwhile, introducing the Exo III-assisted target recycling strategy further amplifies the ECL signal, simplifying the construction process. The as-fabricated ECL biosensor exhibits an ultrasensitive detection ability of Hg2 with a broad liner detection range from 100 nM similar to 0.1 fM, and the detection limit can be down to 0.07 fM. Moreover, this ECL biosensor shows excellent stability, reproducibility and selectivity, and is successfully utilized for the detection of Hg2 in seawater with good performance.

Volume:394

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Translation or Not:no