CdS-Modified TiO₂ Nanotubes with Heterojunction Structure: A Photoelectrochemical Sensor for Glutathione

Area of Science:

• Materials Science
• Electrochemistry
• Biotechnology

Background:

• Heterojunction structures in semiconductors prevent electron-hole recombination, enhancing photoelectric properties.
• Titanium dioxide (TiO2) nanotubes serve as effective carriers for fabricating advanced sensor materials.

Purpose of the Study:

• To fabricate Cadmium Sulfide-Titanium Dioxide Nanotube (CdS-TiO2NTs) heterojunctions for a photoelectrochemical (PEC) sensor.
• To evaluate the PEC performance and sensitivity of the CdS-TiO2NTs sensor under visible light for glutathione (GSH) detection.

Main Methods:

• Hydrothermal-impregnation method was used to prepare TiO2 nanotubes.
• CdS nanoparticles were synthesized onto TiO2 nanotubes to form CdS-TiO2NTs heterojunctions.
• Fabricated CdS-TiO2NTs were used as the electrode for a PEC biosensor.

Main Results:

• The CdS-TiO2NTs electrode exhibited good photoelectrochemical performance under visible light due to the heterojunction structure.
• A linear response was observed for glutathione (GSH) concentrations ranging from 2 to 16 mM.
• The sensor achieved a sensitivity of 102.9 µA·mM⁻¹ cm⁻² and a limit of detection (LOD) of 27.7 µM for GSH.

Conclusions:

• The developed CdS-TiO2NTs heterojunction material shows potential for sensitive and stable PEC biosensing applications.
• This study highlights the effectiveness of heterojunction engineering in semiconductor-based biosensors.
• The fabricated biosensor offers a promising platform for visible-light-driven electrochemical detection.