Interface electronic engineering of molybdenum sulfide/MXene hybrids for highly efficient biomimetic sensors

Interface regulation plays a key role in the electrochemical performance for biosensors. By controlling the interfacial interaction, the electronic structure of active species can be adjusted effectively at micro and nano-level, which results in the optimal reaction energy barrier. Herein, we propose an interface electronic engineering scheme to design a strongly coupled 1T phase molybdenum sulfide (1T-MoS 2 )/MXene hybrids for constructing an efficient electrocatalytic biomimetic sensor. The local electronic and atomic structures of the 1T-MoS 2 /Ti 3 C 2 T X are comprehensively studied by synchrotron radiation-based X-ray photoelectron spectroscopy (XPS), as well as X-ray absorption spectroscopy (XAS) at atomic level. Experiments and theoretical calculations show that there are interfacial stresses, atomic defects and adjustable bond-length between MoS 2 /MXene nanosheets, which can significantly promote biomolecular adsorption and rapid electron transfer to achieve excellent electrochemical activity and reaction kinetics. The 1T-MoS 2/ Ti 3 C 2 T X modified electrode shows ultra high sensitivity of 1.198 µA/µM for dopamine detection with low limit of 0.05 µM. We anticipate that the interface electronic engineering investigation could provide a basic idea for guiding the exploration of advanced biosensors with high sensitivity and low detection limit.