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    • Keywords


      Mercury sensor; fluorescent probe; fluorescence sensor; DNA conjugated core–shell nanoparticles; fluorescence resonance energy transfer; quantum dots.

    • Abstract


      Si@SiO$_2$ core–shell nanoparticles were proposed for the development of fluorescent mercury sensor, wh1455-1462ichalso offers a promising alternative to toxic quantum dots (QD)-based heavy metal detection tools. In this study, a sensitivefluorescent assay based on DNA-labelled Si@SiO$_2$ core–shell nanoparticles for the detection of mercury (II) in environmentalsamples was investigated. Probe DNA was conjugated on the surface of the Si@SiO$_2$ core–shell nanoparticles via 5$^{\circ}$-terminal-SH (thiol group) reaction. The detection protocol was based on the DNA hybridization resulted from the formation of mercury-mediated (thymine–Hg$^{2+}$–thymine) base pairs which leave a fluorescent QD on the surface of quartz glass. The synthesized Si@SiO$_2$ core–shell nanoparticle showed a broad emission peak with strong intensity in the UV range around 423 nm. Transmission electronic microscope (TEM) images confirmed the presence of a uniform core–shell structure with Si core nanoparticles with a particle size ranging from 70 to 80 nm and silica shell thickness of about $10\pm 2$ nm. Overall, ourfindings highlighted that the developed assay can detect Hg$^{2+}$ ions in aqueous solution as low as 0.92 nM concentration. In addition, the labelled Si@SiO$_2$ core–shell nanoparticles showed prominence sensitivity, acceptable precision, reproducibility and stability, and could be readily applied to environmental sampling systems for Hg$^{2+}$ monitoring.

    • Author Affiliations



      1. Department of Chemistry, Anna University, Guindy, Chennai 600 025, India
      2. Department of Biotechnology, Thiruvalluvar University, Vellore 632 115, India
      3. Department of Zoology, Bharathiar University, Coimbatore 641 046, India
      4. Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy
      5. The BioRobotics Institute, Sant’Anna School of Advanced Studies, Viale Rinaldo Piaggio 34, Pontedera 56025, Italy
      6. Department of Chemistry, Thiruvalluvar University, Vellore 632 115, India
    • Dates


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