Periodically Patterned Au-TiO₂ Heterostructures for Photoelectrochemical Sensor

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Developing sensitive and stable biosensors is crucial for disease diagnostics.
• Plasmonic nanomaterials offer unique optical properties for enhanced sensing.
• Photoelectrochemical (PEC) detection provides a sensitive method for analyte quantification.

Purpose of the Study:

• To fabricate and characterize a novel Au nanorods in TiO2 nanocavities (Au NRs@TiO2) heterostructure.
• To utilize this Au NRs@TiO2 platform for the photoelectrochemical detection of glucose and lactose.
• To investigate the enhanced sensing properties, stability, and reusability of the developed sensor.

Main Methods:

• Fabrication of Au NRs@TiO2 heterostructures via magnetron sputtering and thermal dewetting.
• Photoelectrochemical detection of glucose and lactose using the Au NRs@TiO2 platform.
• Evaluation of sensor performance, including sensitivity, detection limit, selectivity, and stability.

Main Results:

• The Au NRs@TiO2 heterostructure exhibited superior sensing properties due to localized surface plasmon resonance (LSPR) and accelerated charge transfer.
• Achieved a low detection limit of 1 μM for glucose and 10 μM for lactose.
• Demonstrated high sensitivity (812 μA mM⁻¹ cm⁻² for glucose, 270 μA mM⁻¹ cm⁻² for lactose) without enzyme addition.
• Exhibited excellent selectivity and stability over 8 weeks.

Conclusions:

• The developed Au NRs@TiO2 heterostructure is a promising plasmonic sensing platform for efficient photoelectrochemical detection of glucose and lactose.
• The sensor's enhanced performance is attributed to the synergistic effects of LSPR, improved charge dynamics, and stable architecture.
• The cost-effective fabrication and broad applicability suggest potential for other photoelectrochemical sensing applications.