title: Graphene-based hybrid for enantioselective sensing applications.
abstract: Chirality is a major field of research of chemical biology and is essential in pharmacology. Accordingly, approaches for distinguishing between different chiral forms of a compound are of great interest. We report on an efficient and generic enantioselective sensor that is achieved by coupling reduced graphene oxide with γ-cyclodextrin (rGO/γ-CD). The enantioselective sensing capability of the resulting structure was operated in both electrical and optical mode for of tryptophan enantiomers (D-/L-Trp). In this sense, voltammetric and photoluminescence measurements were conducted and the experimental results were compared to molecular docking method. We gain insight into the occurring recognition mechanism with selectivity toward D- and L-Trp as shown in voltammetric, photoluminescence and molecular docking responses. As an enantioselective solid phase on an electrochemical transducer, thanks to the different dimensional interaction of enantiomers with hybrid material, a discrepancy occurs in the Gibbs free energy leading to a difference in oxidation peak potential as observed in electrochemical measurements. The optical sensing principle is based on the energy transfer phenomenon that occurs between photoexcited D-/L-Trp enantiomers and rGO/γ-CD giving rise to an enantioselective photoluminescence quenching due to the tendency of chiral enantiomers to form complexes with γ-CD in different molecular orientations as demonstrated by molecular docking studies. The approach, which is the first demonstration of applicability of molecular docking to show both enantioselective electrochemical and photoluminescence quenching capabilities of a graphene-related hybrid material, is truly new and may have broad interest in combination of experimental and computational methods for enantiosensing of chiral molecules.
authors: Nanobioelectronics & Biosensors Group, Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, Barcelona 08193, Spain; Graduate School of Natural Sciences, Selcuk University, Konya 42030, Turkey; Science and Technology Department, A. K. Education Faculty, Necmettin Erbakan University, Konya 42090, Turkey.
authors: Erhan
authors: E
authors: Zor
authors: Nanobioelectronics & Biosensors Group, Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, Barcelona 08193, Spain.
authors: Eden
authors: E
authors: Morales-Narváez
authors: Department of Chemistry, A. K. Education Faculty, Necmettin Erbakan University, Konya 42090, Turkey.
authors: Sabri
authors: S
authors: Alpaydin
authors: Department of Chemistry, A. K. Education Faculty, Necmettin Erbakan University, Konya 42090, Turkey.
authors: Haluk
authors: H
authors: Bingol
authors: Advanced Technology Research and Application Center, Selcuk University, Konya 42030, Turkey. Electronic address: ersozm@gmail.com.
authors: Mustafa
authors: M
authors: Ersoz
authors: Nanobioelectronics & Biosensors Group, Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, Barcelona 08193, Spain; ICREA, Pg. Lluís Companys 23, Barcelona 08010, Spain. Electronic address: arben.merkoci@icn2.cat.
authors: Arben
authors: A
authors: Merkoçi
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods; D006108:Graphite / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods; D062105:Molecular Docking Simulation; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D013237:Stereoisomerism; D013816:Thermodynamics; D014364:Tryptophan / Q000737:chemistry*; D047408:gamma-Cyclodextrins / Q000737:chemistry*
chemical_list: D010087:Oxides; D047408:gamma-Cyclodextrins; D006108:Graphite; D014364:Tryptophan; C023792:gamma-cyclodextrin
keywords: Cyclodextrin; Enantioselectivity; Graphene oxide; Molecular docking; Sensor