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Spinel Cobalt Ferrite Nanoparticles for Sensing Phosphate Ions in Aqueous Media and Biological Samples
journal contribution
posted on 2020-03-16, 15:20 authored by Gabriela
P. Ratkovski, Kamila T. O. do Nascimento, Graciela C. Pedro, Danilo R. Ratkovski, Filipe D. S. Gorza, Romário
J. da Silva, Bruna G. Maciel, Lizeth C. Mojica-Sánchez, Celso P. de MeloPhosphate
ions perform a variety of functions in metabolic processes
and are essential for all living organisms. The determination of the
concentration of phosphate ions is useful in clinical diagnosis of
various diseases as an inadequate phosphate level could lead to many
health problems. In the search for a cost-effective method of fast
monitoring, we investigated the use of cobalt ferrite nanoparticles
(CoFeNPs) in the selective recognition of phosphate ions dissolved
in aqueous media and more complex samples, such as human blood serum.
We prepared these NPs by a chemical coprecipitation route and subjected
them to annealing at 600 °C for 1 h. The successful formation
of the NPs was confirmed by Fourier transform infrared spectroscopy,
X-ray diffraction, transmission electron microscopy, and hysteresis
loop measurements. The NPs exhibited a ferrimagnetic behavior, a spinel-type
crystalline structure, and hexagonal shape in the nanoscale range.
We demonstrated that CoFeNPs containing immobilized fluorescent-labeled
single-chain DNA (ssDNA*) probes can be applied for the fast selective
detection of phosphate ions dissolved in a liquid medium. We have
explored the fact that phosphate groups can displace ssDNA* probes
attached to the nanoparticles, therefore causing a perceptible change
in the fluorescence signal of the supernatant liquid. This detection
method has been tested for the sensing of phosphate ions present both
in aqueous solutions and in biological samples, with excellent selectivity
and a low limit of detection (∼1.75 nM).