Self-reinforced D-MOF and autocatalytic AuPd@SnS2 dual-wavelength electrochemiluminescence biosensor for detection of ctDNA and CEA

Abstract

Trace detection of circulating tumor DNA (ctDNA) and CEA is of great significance for early prevention and diagnosis of cancer. In this work, the well electrochemiluminescence (ECL) of the dual-ligand metal-organic frameworks (D-MOFs) and AuPd@SnS2 QDs nuclear-satellite conjugate was newly explored, and a dual-wavelength biosensing platform based on ECL energy transfer between D-MOFs and AuPd NPs coupled with catalytic effect of AuPd NPs on ECL of SnS2 QDs was developed for detection of trace ctDNA and CEA. Here, thanks to the ordered heterogeneous arrangement and network charge transfer of the luminescent ligand, the prepared D-MOF exhibits highly enhanced ECL without exogenous co-reactants. Target ctDNA was exponentially amplified using an entropy-driven DNA cycle amplification strategy to obtain bandage DNA, which triggered the DNA walker to connect the AuPd@SnS2 core-satellite probe to the electrode. Therefore, the ECL ratio of D-MOF and sensitized SnS2 at 535 nm and 650 nm was used to achieve ultrasensitive detection of trace ctDNA. Moreover, the specific recognition of target CEA to T1 DNA induced changes in dual-wavelength signals to achieve further detection of CEA, and ensure the accuracy of cancer analysis. The work opened up two novel ECL materials and developed a novel ECL biosensor for rapid detection of double tumor markers, providing a new way for early prevention and diagnosis of actual cancer.