Comprehensive Screen of Metal Oxide Nanoparticles for DNA Adsorption, Fluorescence Quenching, and Anion Discrimination

Abstract

While DNA has been quite successful in metal cation detection, anion detectioin remains challenging due to the charge repulsion. Metal oxides represent a very important class of materials, and different oxides might interact with anions differently. In this work, a comprehensive screen of common metal oxide nanoparticles (MONPs) was carried out for their ability to adsorb DNA, quench fluorescence, and release adsorbed DNA in the presence of target anions. A total of 19 MONPs were studied, including Al2O3, CeO2, CoO, Co3O4, Cr2O3, Fe2O3, Fe3O4, In2O3, ITO, Mn2O3, NiO, SiO2, SnO2, a-TiO2 (anatase), r-TiO2 (rutile), WO3, Y2O3, ZnO, ZrO2. These MONPs have different DNA adsorption affinity. Some adsorb DNA without quenching the fluorescence, while others strongly quench adsorbed fluorophores. They also display different affinity toward anions probed by DNA desorption. Finally CeO2, Fe3O4, and ZnO were used to form a sensor array to discriminate phosphate, arsenate, and arsenite from the rest using linear discriminant analysis.This study not only provides a solution for anion discrimination using DNA as a signaling molecule, but also provides insights into the interface of metal oxides and DNA.

Adsorption of Selenite and Selenate by Metal Oxides Studied with Fluorescent DNA Probes for Analytical Application

“…DNA is a polyanion with a phosphate backbone, and previous studies suggested that DNA adsorption by a few oxides (e.g. CeO 2 , Fe 3 O 4 , and TiO 2 ) occurred mainly via its phosphate backbone [24,25,29,30]. Figure 1b depicts such an interaction.…”

“…For example, it is well known that arsenate has a strong affinity with iron oxide and this has been used for remediation of arsenic species from the environment [23]. We took advantage of the competitive adsorption of DNA and arsenate for its detection [24][25][26]. Similarly, hydrogen peroxide can displace DNA from cerium oxide [27], while fluoride can enhance its catalytic activity [28].…”

Optical biosensors based on ZnO nanostructures: advantages and perspectives. A review

“…The covalent binding involves a cross-linking agent between ZnO surface and molecules of the bioselective layer, which provides a significant structure of the bioselective layer and improves the biorecognition [89,47,78,81,87,88].…”

“…Amine (-NH2) and thiol (-SH2) groups are formed after treatment with aminosilanes and mercaptosilanes, respectively [47,89]. The direct immobilization of protein through the interaction between amine and carboxyl groups after APTES silanization of ZnO surface has been investigated as well [78,81]. In the case of thiol-based silanizated ZnO surface, one more step needed for a protein immobilization [47,89].…”

Comparison of MoS2, WS2, and Graphene Oxide for DNA Adsorption and Sensing

“…For example, DNA uses its phosphate to adsorb onto many metal oxides, 45 while uses its base coordination to bind to gold nanoparticles. 46 To probe possible chemical interactions, we next challenged the samples with 10 mM free inorganic phosphate or 1 mM adenosine.…”