Enantioselective recognition of amino acid based on electrochemical deposition and X-ray diffraction technology

Addition of D-Asp in the electrochemical deposition process of Bismuth film resulted the generation of a new diffraction peak in X-ray diffraction (XRD) spectrum. This phenomenon was not observed in the situation of L-Asp. The new diffraction peak might suggest D-Asp could result in the generation of a specific Bismuth structure. Enantioselective recognition of D- and L-Asp can be realized based on this new XRD peak. The limit of detection was determined to be 3.5 × 10^-8 and 1.7 × 10^-8 mol L^-1 for D- and L-Asp, respectively. The XRD spectra of electrodeposited Copper films fabricated in the presence of D- or L-Asp showed different lattice plane diffraction peak intensity ratios. The reason was believed to be chirality induced different binding capabilities of Asp enantiomers that influenced Copper film growth. Therefore, the combination of electrochemical deposition using Copper as metal source and XRD technology can be used to achieve enantioselective recognition of Asp. The limit of detection for D- and L-Asp were determined to be 1.5 × 10^-10 and 1.2 × 10^-11 mol L^-1, respectively.