Using Enantioselective Indicator Displacement Assays To Determine the Enantiomeric Excess of α-Amino Acids

Abstract

Enantioselective indicator displacement assays (eIDAs) were used for the determination of enantiomeric excess (ee) of alpha-amino acids as an alternative to the labor-intensive technique of chromatography. In this study, eIDAs were implemented by the use of two chiral receptors [(Cu(II)(1)](2+), [Cu(II)(2)](2+)) in conjunction with the indicator chrome azurol S. The two receptors were able to enantioselectively discriminate 13 of the 17 analyzed alpha-amino acids. Enantiomeric excess calibration curves were made using both receptors and then used to analyze true test samples to check the system's ability to determine ee accurately. The proposed method uses a conventional UV-vis spectrophotometer to monitor the colorimetric signal, which allows for a potential high-throughput screening (HTS) method for determining ee. The techniques created consistently produced results accurate enough for rapid preliminary determination of ee.

A New Chemosensing Ensemble for Colorimetric Detection of Oxalate in Water

“…[1][2][3][4][5][6] Colorimetric sensing of a specific anion is a particularly attractive research topic because of its simplicity and naked eyes detectable nature, which allows visual detection of anions without resort to expensive spectroscopic instrumentation. 1,2,[7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Dicarboxylates are among the most attractive targets for anion recognition and sensing due to their critical roles in numerous metabolic processes such as the generation of highenergy phosphate bonds and the biosynthesis of important intermediates. 22,23 Detection of oxalate is particularly useful in food chemistry and in clinical analysis.…”

Chiral Recognition by Fluorescence: One Measurement for Two Parameters

“…To date, a number of techniques are under development for the high-throughput enantiomeric composition determination [13][14][15][16][17], including time resolved IR-thermographic method [18][19][20][21], electron spray mass spectrometry [22][23][24][25][26], capillary electrophoresis [27], UV/Vis [28][29][30], circular dichroism [31,32], and fluorescence [33,34]. Among these approaches, optical methods have been attracting increasing attention due to their ability for quick data collection and compatibility with high-throughput screening system.…”

Colorimetric sensing of anions in water using ratiometric indicator-displacement assay

“…In recent years, indicator-displacement assay (IDA) has been widely investigated [25][26][27][28]. This method is largely derived from the color change of colorimetric or fluorescent ligands, which compete with analytes for binding to the receptors.…”