ORAOV 1 Detection Made with Metal Organic Frameworks Based on Ti₃C₂T_x MXene

In this work, a two-dimensional (2D) MOF sheet with electrochemiluminescence (ECL) activity is prepared with Ti₃C₂T_x MXene as the metal precursor and the meso-tetra(4-carboxyl-phenyl) porphyrin (H₂TCPP) as the organic ligand. The atomically thin 2D Ti₃C₂T_x MXene is utilized as the metal precursor and soft template to produce the MOF with a 2D nanosheet morphology (Ti₃C₂T_x-PMOF). Ti₃C₂T_x MXene is a kind of strong electron acceptor, which can deprotonate H₂TCPP due to the high electronegativity and low work function of its terminal atoms. The deprotonated H₂TCPP continues to bind with Ti atoms to form the 2D MOF sheet. The ECL activity is inherited from H₂TCPP and stabilized by introducing Ag NPs. Then, we construct an ECL biosensor based on the Ag NPs/Ti₃C₂T_x-PMOF to detect the oral cancer overexpressed 1 (ORAOV 1). A bipedal three-dimensional DNA walker strategy is adopted to further improve the biosensor sensitivity. As expected, the biosensor exhibits sterling sensitivity and selectivity. The ECL biosensor responds linearly to ORAOV 1 concentrations in the range of 10 fM-1 nM, and the detection limit is as low as 3.3 fM (S/N = 3). It means that Ag NPs/Ti₃C₂T_x-PMOF is a potential material to design and construct the high-performance ECL biosensors.