Assembly of MoS2 nanosheet-TiO2 nanorod heterostructure as sensor scaffold for photoelectrochemical biosensing

•MoS2 nanosheets were grown on TiO2 nanorods to obtain a heterostructure.•The thickness of MoS2 nanosheets in the composite is much thinner than that of MoS2 microspheres.•Photoelectrochemistry (PEC) of the heterostructure is superior to that of the single component under visible irradiation.•Glucose oxidase (GOx) PEC biosensor was developed based on the heterostructure.•The performance of PEC GOx sensor was evaluated

In the present work, MoS2 nanosheets were composited with TiO2 nanorods to obtain a heterostructure with improved photoelectrochemical (PEC) performance. TiO2 nanorods were initially prepared using a hydrothermal method, and then MoS2 nanosheets were synthesized using TiO2 nanorods as the substrates. Various spectroscopic and microscopic methods were used to investigate the morphology and composition of the composite. Electrochemical impedance spectroscopy was also conducted to demonstrate the excellent electrical conductivity of the composite. The bioactivity of glucose oxidase (GOx) to glucose was validated with cyclic voltammetry in air-saturated solution. Finally, a PEC biosensor was fabricated by immobilizing GOx on MoS2 nanosheet-TiO2 nanorod composite modified ITO electrode. Owing to the high specific surface area, good conductivity, excellent biocompatibility and small band gap associated with this composite, the PEC glucose biosensor exhibited a dynamic range of 0.1-10.5 mM, sensitivity of 0.81 μA mM−1, and a detection limit of 0.015 mM within the visible spectrum.