Deep eutectic solvent-delaminated MXene decorated with Co Ni MOF as a co-reactant accelerator for ultrasensitive electrochemiluminescent detection of H2O2 released from cancer cells
Seyyed Mehdi Khoshfetrat, Amirhossein Hatami
Abstract
Hydrogen peroxide (H 2 O 2 ), a key marker of reactive oxygen species (ROS), plays a critical role in early cancer detection and diagnosis. However, its low physiological concentrations, rapid diffusion, and instability pose challenges for accurate quantification. In this study, MXene/DES/Co-Ni MOF nanocomposites were developed to enhance detection precision and signal output in luminol-H 2 O 2 electrochemiluminescence (ECL) sensing, enabling real-time monitoring of H 2 O 2 release from cancer cells. This was achieved through structural engineering of deep eutectic solvent (DES)-delaminated Ti 3 C 2 MXene, providing expanded interlayer spacing and excellent electrical conductivity, facilitating Co Ni MOF integration and optimizing electrode–electrolyte interactions. The porous Co Ni MOF framework effectively encapsulates luminol molecules, establishing a nanoconfined environment that stabilizes reactive species such as hydroxyl radicals ( • OH) and superoxide anions ( O 2 • − ). Importantly, the nanocomposite functions not only as a conductive scaffold but also as an enzyme-mimetic co-reactant accelerator, catalyzing H 2 O 2 decomposition and enhancing ROS generation efficiency. This dual functionality markedly amplifies the ECL response and promotes efficient luminol oxidation. The resulting sensing platform demonstrated ultrasensitive and selective detection of H 2 O 2 , achieving a detection limit as low as 0.006 nM across a wide linear range of 0.01 nM to 750 μM. Furthermore, the system was successfully employed for real-time monitoring of H 2 O 2 release from MCF-7 breast cancer cells stimulated with ascorbic acid. The sensor exhibited excellent anti-interference capability, broad dynamic detection ranges from 35 to 150 × 10 3 cells, and high sensitivity with a detection limit as low as 15 cells, enabling reliable differentiation between cancerous and normal populations.