Multitasking carbohydrate-functionalized 2D germanane with implanted supramolecular stereodiscrimination ability

• Direct synthesis of 2D–GeCD via thiolation chemistry. • Passivation of the 2D material via Ge–S bond formation. • 2D germanene derivative with implanted supramolecular features. • Multitasking activity of 2D–GeCD for discrimination of enantiomers and diastereomers. • Dual-mode discrimination of chiral tryptophan using optical and electrochemical readouts. Due to their promising photoelectronic features, 2D–Germanane (2D–GeH) and their ligand-terminated derivatives (2D–GeR) have garnered significant attention in the Materials Science community. To date, the synthesis of 2D–GeR relies on a tedious topochemical reaction, a fact that not only limits the variety of R ligands that can be incorporated but also restricts their stability and applicability. Herein, a highly stable carbohydrate-based 2D germanane derivative with built-in stereodiscrimination ability has been synthesized via a direct covalent immobilization of a cyclic oligosaccharide selector ( viz. thiolated β-cyclodextrin, CD–SH) onto 2D–GeH. By taking advantage of the CD affinity to accommodate different stereoisomers through supramolecular host–guest interactions, the multitasking activity of the resulting 2D–GeCD has been explored for the selective discrimination of enantiomers and diastereomers. Overall, this chemical approach is general and opens up the development of multitasking 2D–GeR derivatives by incorporating supramolecular features, which can be easily extended to a wide range of bio-molecules by tailoring the stereometric host–guest encapsulation.