Zusammenfassung
We report on a systematic study on the reactivity of the pyrylium dye Py-1 toward various classes of amines (primary aliphatic, primary aromatic, secondary, tertiary) and its use in environmental sensing of amines. While most primary aliphatic amines react almost quantitatively with Py-1 within 10 min, sterically hindered primary aliphatic amines and primary aromatic amines react more slowly. ...
Zusammenfassung
We report on a systematic study on the reactivity of the pyrylium dye Py-1 toward various classes of amines (primary aliphatic, primary aromatic, secondary, tertiary) and its use in environmental sensing of amines. While most primary aliphatic amines react almost quantitatively with Py-1 within 10 min, sterically hindered primary aliphatic amines and primary aromatic amines react more slowly. Secondary and tertiary amines just induce a decomposition of the chromophore of Py-1 but do not yield a fluorescent product. This makes Py-1 a suitable receptor and transducer in an optical sensing microplate for rapid screening of primary aliphatic amines in water and soil samples. Py-1 is embedded into a polymeric cocktail, which is deposited on the bottom of wells in microtiter plates to yield a high-throughput fluorescence sensing tool. On reaction with primary aliphatic amines, a significant fluorescence increase (lambda(exc) =485 nm/lambda(em) = 620 nm) of the sensor spots is detected in a standard microplate reader after 10 min incubation at 25 degrees C. The linear calibration plots of eight primary aliphatic amines are in the range of 0.350-70.0 mu g mL(-1). The limits of detection (LODs) are from 0.119 to 0.589 mu g mL(-1) and the limits of quantitation (LOQs) are from 0.399 to 1.965 mu g mL(-1). We further show that the sensing plate is suitable for sensing mixtures of primary amines and that the total content of amines (TAC) found is a good measure for the sum of the contents of the individual amines present. Finally, the sensing plate was successfully applied to the quantitative analysis of primary aliphatic amines in 3 samples of water and soil, respectively. (C) 2012 Elsevier B.V. All rights reserved.