Selective and fast growth of CdS nanocrystals on zinc (II) metal-organic framework architectures for photoelectrochemical response and electrochemical immunosensor of foot-and-mouth disease virus

The integration of cadmium sulfide (CdS) and metal organic frameworks (MOFs) has shown promise in applications such as photocatalysis and sensing. Herein, a sensitive electrochemical immunosensor based on a room temperature, simple and fast aqueous synthetic strategy of in-situ selective growth nanocystalline CdS on zinc metal organic framework (CdS@Zn-MOF) is reported. We investigated the possibility of growth CdS on various MOFs, synthesizing by electrosynthesis or solution phase syntheses with different metal ions (e.g. Zn2+, Cu2+, Fe3+, Co2+, Zr4+) and organic ligands (e.g. 1,3,5-benzenetricarboxylic acid, 2-methylimidazole, 1,4-benzenedicarboxylic acid, 2-aminoterephthalic acid). This simple experiment process proved that CdS nanocrystalline can selectively grow on varied structures Zn-MOFs with different organic ligands. The synthesis, characterization and mechanisms involved in the formation of this composite material was explored carefully and thoroughly. The unique properties of this composite presented a promising photoelectrochemical and electrochemical applications. Therefore, a sensitive Zn-MOF-labeled amperometric immunosensor based on this strategy for the detection of foot-and-mouth disease virus (FMDV) was developed. The logarithm FMDV concentration was range from 0.5 fg mL(-1) to 5 ng mL(-1) with a low detection limit of 0.05 fg mL(-1). Moreover, this proposed sensor with good selectivity, acceptable reproducibility, and stability was successfully applied to detect FMDV in actual blood sample. Furthermore, this method of growth the CdS nanocrystalline in situ on a Zn-MOF device structure or platform also provides a new horizon for future optoelectronic applications.