Chiral analysis is of significant importance for living organisms since chirality is the fundamental phenomenon in nature. In this work, a bifunctional electrochemiluminescent (ECL) platform is constructed for chiral discrimination and chiral sensing. 3-Mercaptopropionic acid-functionalized CdSe quantum dots (CdSe QDs) are combined with aminated TiO2 nanotubes (NH2-TiNTs) via amidation. The resultant CdSe QDs/TiNTs display significantly enhanced ECL signals due to the synergistic effect between CdSe QDs and TiNTs, which are then used for the chiral discrimination of the isomers of nine chiral amino acids (AAs) in the presence of d-AA oxidase (DAAO). DAAO can selectively catalyze the oxidation of d-AAs to generate H2O2, which acts as the coreaction reagent and triggers the ECL signals of CdSe QDs/TiNTs, and thus, the isomers of the nine chiral AAs can be effectively discriminated. In addition, the as-constructed ECL platform can also be used for the sensitive detection of d-AAs in the presence of DAAO with a wide linear range and a low limit of detection. These findings suggest that the CdSe QDs/TiNTs can work as a bifunctional ECL platform (chiral discrimination and chiral sensing), which might be an advanced ECL platform for biomedical applications.

A novel Zn‐coordination covalent porphyrin assembly (TCPP‐BZA‐Zn) is designed. The assembly structure is synthesized through the amidation reaction between the porphyrin terminal carboxyl group and the amino group of benzylamine (BZA), and further assembled through π–π stacking. In particular, the inherently ordered structure of TCPP‐BZA‐Zn with Zn as the catalytic active center endows the porphyrin assembly structure with several obvious advantages, such as high ion transport properties and high electrocatalytic performance. In the presence of hydrogen peroxide as a co‐reaction reagent, TCPP‐BZA‐Zn/GCE showed excellent ECL behavior. The amplification phenomenon of ECL was further studied by cyclic voltammetry and the corresponding mechanism was proposed. Based on TCPP‐BZA‐Zn, an electrochemiluminescence sensor was constructed for copper ion detection. The ECL intensity of the sensor shows a good linear relationship with the concentration of copper ion in the range of 10 nM–1 mM, and the detection limit is 1.3 nM.

Science the biological activities of chiral enantiomers are often different or even opposite, their chiral recognition is of great significance. A new assembly structure named TCPP-Zn-(S)-BINOL was obtained based on the interaction between chiral binaphthol (BINOL) and the porphyrin-based MOF structure formed by Meso-Tetra(4-carboxyphenyl)porphine (TCPP) and Zn2+, and a new chiral sensor was designed relying on TCPP-Zn-(S)-BINOL. The chiral platform was designed by using binaphthol as a chiral recognizer and the porphyrin MOF as an emitter, which can recognize tyrosine (Tyr) enantiomers via the electrochemiluminescence (ECL) method. According to density functional theory (DFT), TCPP-Zn-(S)-BINOL has a different affinity with L/D-Tyr due to the different strength of the hydrogen bond between chiral ligand BINOL and the tyrosine (Tyr) enantiomer. It will be more suitable for combination with L-Tyr, and the presence of L-Tyr will increase the ECL intensity of the modified electrode via the catalytic reduction of co-reactant reagents, achieving the purpose of the chiral recognition of Tyr enantiomers. These findings show that TCPP-Zn-(S)-BINOL can be used as an advanced ECL chiral recognition platform for biomedical applications.