CdSe/TiO₂NTs Heterojunction-Based Nonenzymatic Photoelectrochemical Sensor for Glucose Detection

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Semiconductor heterojunctions offer superior light utilization and photoelectric performance compared to single semiconductors.
• Titanium dioxide (TiO2) nanotubes provide a stable and effective platform for creating advanced heterojunctions.

Purpose of the Study:

• To synthesize and characterize CdSe/TiO2NTs heterojunctions for photoelectrochemical (PEC) sensing applications.
• To investigate the enhanced light absorption and reduced carrier recombination in CdSe/TiO2NTs.
• To evaluate the sensor's performance for glucose detection, including linearity, detection limit, selectivity, and stability.

Main Methods:

• Hydrothermal synthesis was employed to fabricate CdSe/TiO2NTs heterojunctions.
• Characterization techniques included X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Photoluminescence (PL), UV-Vis spectroscopy, and Electrochemical Impedance Spectroscopy (EIS).
• Photoelectrochemical measurements were conducted under visible light irradiation to assess sensor performance.

Main Results:

• CdSe/TiO2NTs heterojunctions demonstrated significantly higher visible light absorption and reduced photogenerated carrier recombination compared to pure TiO2.
• Theoretical calculations confirmed effective separation of electrons and holes within the heterojunction.
• A linear relationship was observed between glucose concentration (10-90 μM) and photocurrent, with a low detection limit of 3.1 μM.
• The CdSe/TiO2NTs sensor exhibited excellent selectivity and stability.

Conclusions:

• The synthesized CdSe/TiO2NTs heterojunctions show great potential for sensitive and selective photoelectrochemical glucose sensing.
• The enhanced performance is attributed to improved light utilization and efficient charge separation at the heterojunction interface.
• The study elucidates the PEC sensing mechanism of CdSe/TiO2NTs, paving the way for further development in biosensing applications.