A novel Cu-MOFs nanosheet/BiVO₄ nanorod-based ECL sensor for colorectal cancer diagnosis

Although luminescence metal organic framework (MOFs) has displayed the significant advantages, the limitations in the electrochemical performance (e.g. rapid charge recombination rates and inadequate charge transport) limited the sensing application of MOFs. Herein, a novel Cu-MOFs/BiVO₄ nanorod-based electrogenerated chemiluminescence (ECL) sensor has been developed. Firstly, Cu-MOFs with strong luminescence were synthesized via the three-layer approach as ECL emitter. Furthermore, BiVO₄ nanorods was modified on the electrode as the actuator to improve the electrochemical activity of Cu-MOFs in the ECL process. As an n-type semiconductor, BiVO₄ formed a complementary structure with p-type semiconductor Cu-MOF. Therefore, electrons in the conduction band of BiVO₄ transferred to that of Cu-MOF. As a result, more electrons reacted with coreactant on the surface of Cu-MOF, which effectively enhanced the ECL performance of 2D Cu-MOFs nanosheets. As a result, the quantitation of KRAS gene was realized in the linear range of 0.1 pM-1 nM with a detection limit of 0.02 fM. Moreover, the detection of KRAS gene in actual colorectal cancer samples was also carried out with good recovery, which offered a broad application possibility for ECL research and clinical analysis.