Electrochemical Recognition of Chiral Molecules with Poly(4‐bromoaniline) Modified Gold Electrode

Abstract

A poly(4-bromoaniline) (PBA) film is electrochemically synthesized on a gold electrode for the recognition of amino acids enantiomers. Scanning electron microscopy measurements show that the porous PBA films are made up of nano-ribbons. At the PBA modified Au electrode differential pulse voltammograms of l-and d-glutamic acids not only have very different current densities, but also produce different waveforms, providing an intuitive way to differentiate the two chiral molecules. Similar results are obtained in analyzing l-and d-aspartic acids. Control experiments suggest that the observed sensing behavior arises from synergistic interactions between Au and the PBA film, where polymerization at the meta-position creates a steric structure needed for differentiating chiral molecules.

Pair of (Hg2II)3L2 Chiral Cages and Successive Transformation into (HgII)3L2 Chiral Cages: Chiral DOPA Recognition via Chiral Cages

“…Recently, research on desirable chiral coordination architectures has expanded into task-specific practical applications such as purification of chiral pharmaceuticals, recognition of chiral pollutants, preparation of bioactive foods, chiral catalysis, chiral isolation, and environmental problems. − Noteworthy modes of action of some coordination cages have been assigned, − and research on chiral cages that can selectively recognize useful chiral chemicals is a particularly hot research topic. − Both the confined space and the active site of chiral coordination cages are important factors for practical useful applications via specific weak interactions between the coordination cages and substrate molecules. Thus, various useful chiral coordination cages achieved via a stereogenic center, atropisomerism, or noncovalent weak interactions have been designed and constructed by various methodologies. − Numerous studies on the construction and applications of chiral coordination species have been devoted to the enantiorecognition of essential amino acids including chiral l - and d -proline − and to asymmetric catalysis reactions as well. − 3,4-Dihydroxyphenylalanine (DOPA) has been regarded as an important chiral molecule in the fields of medicine, biology, and marine adhesion. − l -DOPA, for instance, has been known to play a crucial role at the clinical level and in neurochemistry with respect to Parkinson′s disease, in contrast to its chiral isomer, inactive and toxic d -DOPA. , Thus, several chiral electroanalysis methods have been applied to distinguish DOPA enantiomers, including those entailing the application of self-assembled monolayers, molecularly imprinted sol–gel films, poly-lysine films, and chiral nanomaterials . However, fabrication of sensitive chiral sensors capable of discriminating DOPA enantiomers remains a fascinatingly challenging task.…”

Pair of chiral 2D silver(i) enantiomers: chiral recognition of l- and d-histidine via differential pulse voltammetry

“…[10][11][12][13][14][15][16][17][18] In order to set-up an efficient system for enantio-recognition of various chiral compounds, a number of electrochemical techniques with attributes including high sensitivity, easy operation, fast speed, and low cost, have been employed. [19][20][21][22][23][24][25][26][27][28] Great efforts have been made to develop an effective chiral electrode surface by utilizing various chiral coordination networks for enantio-recognition of chiral amino acids. [29][30][31][32][33][34] Among the various amino acids, histidine is an essential constituent for humans, animals, microorganisms, and plants.…”

Chiral Pd6L8 Nanocube Pairs: Recognition of Chiral Amino Acids via Electrochemistry

“…Noteworthy research on functional coordination cages has been ongoing, − and, currently, chiral hosts that can selectively interact with ubiquitous chiral guests are a hot topic. − Both the internal space and functional site of chiral hosts are essential factors for practical task-specific functions. Thus, distinct chiral coordination cages via a stereogenic center, atropisomerism, or noncovalent interactions have been synthesized for chiral isolation, enantiorecognition, and chiral catalysis, − the processes of which play a pivotal role in the chiral-recognition field. − The literature has devoted only limited attention to the enantiorecognition of chiral l - and d -proline, − even though chiral proline and their related essential amino acids have been employed in the biosynthesis of proteins and as asymmetric catalysts in diverse organic reactions. , Meanwhile, in order to construct an efficient system for the enantiorecognition of various chiral compounds, various electrochemical techniques have been attracting much attention because of their high sensitivity, simple operation, speed, and low cost. − However, the enantiorecognition of essential amino acids via the oxidation/reduction potentials of chiral coordination hosts based on an efficient electrochemical technology still remains a necessary and challenging task.…”