Label-Free Electrochemiluminescent Determination of DNA Using Luminol and Hemin Functionalized Nanoparticles

Abstract

Luminol and hemin dual-functionalized silica nanoparticles were synthesized using a typical reverse water-in-oil microemulsion protocol. The obtained nanoparticles were further characterized by transmission electron microscopy, scanning electron microscopy, atomic absorption spectrometry, chemiluminescence, and electrochemiluminescence. The results indicated that the luminol and hemin dual-functionalized silica nanoparticles exhibited significantly higher chemiluminescence and electrochemiluminescence intensities than those of luminol functionalized silica nanoparticles due to the catalytic effect of hemin on the chemiluminescence and electrochemiluminescence of luminol. Furthermore, a simple and sensitive label-free electrochemiluminescence DNA biosensor was developed based on the chitosan modified luminol and hemin dual-functionalized silica nanoparticles and a single-stranded DNA probe. The chitosan modified luminol and hemin dual-functionalized silica nanoparticles were immobilized on the surface of an indium-doped tin oxide electrode and the single-stranded DNA probe was immobilized on the surface of the nanoparticles through electrostatic interactions between single-stranded DNA and chitosan, which allowed hybridization with the target DNA sequences. The hybridization events were evaluated by electrochemiluminescence, and only the complementary sequence formed double-stranded DNA with the DNA probe to give strong electrochemiluminescence signals. Finally, the electrochemiluminescence intensity was found to be linearly related to the concentration of the complementary sequence at concentrations from 1.0 × 10⁻¹² to 1.0 × 10⁻⁶mol·L⁻¹ with a detection limit of 5.0 × 10⁻¹³mol·L⁻¹.

Keywords:

• DNA biosensor
• dual-functionalized silica nanoparticles
• electrochemiluminescence
• hemin
• luminol

Additional information

Funding

This research was financially supported by the National Natural Science Foundation of China (No. 21665025), an Outstanding Young Science and Technology Personnel Training Project of the Xinjiang Uyghur Autonomous Region (No. QN2016YX0306), and Key Projects of the Engineering Research Center of Electrochemical Technology and Application (XJNUGCZX122017A01), which are gratefully acknowledged.