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

In the present work, MoS 2 nanosheets were composited with TiO 2 nanorods to obtain a heterostructure with improved photoelectrochemical (PEC) performance. TiO 2 nanorods were initially prepared using a hydrothermal method, and then MoS 2 nanosheets were synthesized using TiO 2 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 MoS 2 nanosheet-TiO 2 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.