Luminescent solid phase for sialic acid determination: a promising sensor for milk‐adulterated samples

Abstract

This article presents the synthesis, characterization and spectroscopic study of silica modified with thenoyltrifluoroacetonate (SilTTA) and coordinated to an europium (III) ion, for the determination of sialic acid (NANA). Elemental analysis and infrared spectroscopy suggest silica functionalization, as well as coordination of beta-diketone to the lanthanide ion. The emission spectra of compound-free and coordinated Eu-SilTTA to NANA showed significant changes with respect to the maximum emission and spectral profile, suggesting that the NANA ion is coordinated to the Eu(III). The values of the phenomenological intensity parameters show an increase in polarizability around the Eu(III) in the case of Eu-SilTTA coordinated to NANA, as expected, since water molecules are less polarizable than sialic acid. The results of the batch assay showed that luminescent silica can be used for sialic acid determination in milk-adulterated samples, with a correlation coefficient of 0.9992; and a detection limit of 0.4 mg/L; relative standard deviation (RSD%) = 0.0028.

Explorations in a galaxy of sialic acids: a review of sensing horizons, motivated by emerging biomedical and nutritional relevance

“…385 Alves et al reported a solid-phase fluorometric assay of Nue5Ac with LDR and LOD 0.4-2000.0 and 0.4 mg L −1 , respectively, by incubating Nue5Ac with EuIJIII)-coordinated silica modified by sodium thenoyltrifluoroacetonate in ethanol (carbonate buffer pH 6) for 3 min and measuring the fluorescence intensity at 615 nm for a photoexcitation at 345 nm. 386 Several photoluminescence assays based on phenylboronic acid linked established fluorophores viz. CdTe, fluorescein isothiocyanate, etc.…”

“…388–391,393 The solid-phase fluorometric assay could provide a wide LDR 1.3–6500 μM with a LOD of 1.3 μM. 386 The ultra-sensitive Cr( iii )-displacement fluorometric assay with fluorescein sodium dye anchored TpPa-1 could provide a wide LDR of 10 nM–10 mM (although in logarithmic scale) with sufficiently low LOD (7.08 nM) without interference from l -proline and urea. 392 However, the fluorescent CdTe quantum dots modified with Sambucus nigra bark lectin could provide lowest LOD (2.1 nM; converted from 0.67 ng mL −1 ) for fluorometric assay of Sia with a moderately wide LDR 3.88 nM–2.2 μM (converted from 12–680 ng mL −1 ) in linear scale without interference in commercial egg products.…”