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Colorimetric Determination of Sialic Acid Based on Boronic Acid-Mediated Aggregation of Gold Nanoparticles

Titilope John Jayeoye, Wilairat Cheewasedtham, Chatchai Putson, Thitima Rujiralai

Mikrochim Acta. 2018 Aug 10;185(9):409.

PMID: 30097735

Abstract:

The authors describe a rapid, sensitive and selective colorimetric assay for sialic acid (SA) based on the use of gold nanoparticles (AuNPs) modified with 3-aminophenylboronic acid (3-APBA) which acts as the recognition probe for SA. 3-APBA contains amino groups and boronic acid groups through which it can assemble on citrate stabilized AuNPs. It reacts with the cis-diol groups of SA by reversible formation of a cyclic boronate ester in slightly acidic buffer. Detection involves the sequential addition of AuNPs, phosphate buffer, 3-APBA and SA in a tube, vortex mixing, acquisition of photographic images or absorption spectra, and calculation of the result. The method is simple, rapid, and does not require cumbersome steps such as the preparation of stable boronic acid functionalized AuNPs as used in colorimetric sensing of saccharides. Under the optimum conditions, the ratio of absorbances at 700 and 520 nm increases linearly in the 0.15-1.00 mM SA concentrations range, and the detection limit is 60 µM. This is comparable to the detection limit obtained in other colorimetric assays reported. Acceptable intra- and inter-day precisions of three SA concentrations (0.50, 1.00 and 2.00 mM) ranged from 1.9-4.2% and 4.2-6.4%, respectively. The efficacy of the method was demonstrated by analyzing simulated human saliva which gave recoveries ranging from 98.7-106.0%. Graphical abstract Schematic of a colorimetric method for detection of sialic acid (SA) in simulated saliva. It is based on aggregation of gold nanoparticles with 3-aminophenyl boronic acid (3-APBA) which assembles on AuNPs while the boronic acid group binds to cis-diols of SA to form a boronate ester.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP1287753427 (6-Methyl-5-quinolinyl)boronic acid (6-Methyl-5-quinolinyl)boronic acid 1287753-42-7 Price
LS7931253 5-cyano-3-pyridinyl boronic acid 5-cyano-3-pyridinyl boronic acid Price
LS793652 3-methoxy-2-hydroxyphenyl boronic acid 3-methoxy-2-hydroxyphenyl boronic acid Price
LS793655 2-hydroxy-3-methylphenyl boronic acid 2-hydroxy-3-methylphenyl boronic acid Price
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