Urchin-Like Chiral Metal–Organic Framework/Reduced Graphene Oxide Nanocomposite for Enantioselective Discrimination of d/l-Tryptophan

An urchin-like chiral metal–organic framework/reduced graphene oxide (urchin-CMOF/rGO) nanocomposite was developed as the electrochemical sensing interface for robust, efficient, and high-selective discrimination of tryptophan (Trp) enantiomers. An urchin-CMOF/rGO nanocomposite was elaborately integrated to combine the amplification of electrical conduction by rGO and the enantioselectivity by asymmetric CMOF. On the basis of this novel nanocomposite-mediated sensor, chiral recognition of d/l-Trp was successfully achieved by the differential potential ratiometric method. Different percentages of Trp racemic mixtures were determined in a good linear relationship with specific peak potentials, which effectively detours the nonspecific signal of concomitant interference from most current-based voltammetries. Even in the complex human cerebrospinal fluid, the simulative ratiometric results of Trp-spiked samples were accurately detected with low false negatives. Additionally, diverse CMOF-regulated hybrid materials have great potential for chiral recognition in pharmaceutical monitoring and biochemical analysis.