A fast and ultrasensitive detection of zinc ions based on "signal on" mode of electrochemiluminescence from single oxygen generated by porphyrin grafted onto palladium nanocubes

Key Words:Zinc compounds;Absorption spectroscopy - Amides - Diagnosis - Fourier transform infrared spectroscopy - Grafting (chemical) - Ions - Molecular biology - Nanocomposites - Oxygen - Palladium - Porphyrins - Proteins - Transcription

Abstract:Zinc ions (Zn²⁺) act as a transcription factor in eukaryotic cells for mediating protein-protein interactions in human healthy. The simple and sensitive detection of Zn²⁺ is the crucial mission in analytical field. This work demonstrated a novel and fast Zn²⁺ detection strategy based on "signal on" mode with electrochemiluminescence (ECL) luminophore, in which singlet oxygen was generated via electrocatalytic reduction of zinc proto-porphyrin IX grafted onto Pd nanocubes (ZnPPIX-Pd NCs). In protocol, Pd NCs were synthetized under hydrothermal conditions and aminated through thermal oxidative polymerization of 3-aminopropyltriethoxysilane (APTES), followed by further linking with PPIX via amide reaction. The resulting PPIX-Pd NCs effectively captured Zn²⁺ in chelation and monitored by Fourier transform infrared (FTIR) spectroscopy and ultraviolet-visible (UV-vis) absorption spectroscopy. By virtue of the metal resonance responses of Pd NCs, an intense monochromic, potential shuffling and enhanced ECL irradiation shows up for the hybrid nanocomposite with H<inf>2</inf>O<inf>2</inf> as the coreactant. To this end, an ultrasensitive method based on the nanocomposite with a "signal-on" model was developed for Zn²⁺ detection with a low detection limit down to 0.38 nM (based on a S/N= 3), excellent precision and high stability. The ECL strategy reveals the potential application in molecular diagnosis and offers a new avenue for bioassay of structural Zn(II) proteins and zinc finger-binding nucleotides.<br/> © 2019 Elsevier B.V.

Volume:290

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Translation or Not:no