Albumin-stabilized gold nanoclusters as viable fluorescent probes in non-titrimetric iodometry for the detection of oxidizing analytes

We describe a simple method for non-titrimetric determination of oxidative species capable of oxidizing iodide to form free iodine. The combined action of iodine and excess iodide leads to the etching of gold nano clusters stabilized with serum albumin. The extent of fluorescence quenching represents a direct signal for the amount of oxidative analytes. Compared to classical iodometry, tedious titration steps are not required and much smaller sample volumes are needed. This new assay provides a convenient means as demonstrated for the quantification of the oxidative analytes nitrite, bromate and periodate, with detection limits (at 3σ) of 11.7 μM, 1.7 μM, and 1.5 μM, respectively. (author)