Sensitive photoelectrochemical sensing of glucose using hematite decorated with NiAl-layered double hydroxides

Hematite (α-Fe₂O₃) is a promising photoelectrode material for photoelectrochemical (PEC) sensors. However, it still suffers from serious surface charge recombination and slow interfacial charge transfer kinetics. In this work, NiAl-layered double hydroxides decorated on α-Fe₂O₃ (NiAl-LDH/α-Fe₂O₃) was successfully fabricated via a facile hydrothermal method. The NiAl-LDH/α-Fe₂O₃ exhibits excellent PEC response toward glucose, with a good linear range from 0.01 to 2 mM, a high sensitivity of 274.7 μA·mM^-1·cm^-2 and a low detection limit of 0.005 mM. NiAl-LDH/α-Fe₂O₃ PEC sensor could be used for glucose determination in various food samples, such as bread, toast and glucose oral solution, which achieved comparable results with that of HPLC. PEC and electrochemical characterizations indicate NiAl-LDH could act as and/or provide active sites for glucose detection, enlarge the band bending and decrease the charge transfer resistance, thus significantly improve the PEC response of α-Fe₂O₃ toward glucose.