Macroporous ordered titanium dioxide (TiO2) inverse opal as a new label-free immunosensor.

Area of Science:

• Materials Science
• Nanotechnology
• Biosensing

Background:

• Photonic crystal materials exhibit high sensitivity to refractive index changes.
• Label-free biosensing offers advantages in simplicity and reduced assay time.
• Titanium dioxide (TiO2) is a versatile material with potential in optical applications.

Purpose of the Study:

• To fabricate a three-dimensionally ordered macroporous (3DOM) TiO2 inverse opal film.
• To develop a label-free immunosensor based on the fabricated TiO2 film.
• To evaluate the sensing performance of the 3DOM TiO2 inverse opal film for protein detection.

Main Methods:

• Fabrication of 3DOM TiO2 inverse opal film via self-assembly.
• Construction of an optical spectrometer using the TiO2 inverse opal film.
• Investigation of sensing performance using human IgG/goat anti-human IgG immunoassay.

Main Results:

• The 3DOM TiO2 inverse opal film demonstrated high sensitivity for protein detection.
• A detection limit of 1 microg mL(-1) (1.5 pg mm(-2)) for protein concentration was achieved.
• The material possesses a large internal surface area, low fluorescence background, and unique optical properties.

Conclusions:

• The 3DOM TiO2 inverse opal film is a promising material for label-free immunosensing.
• Its optical properties and structural characteristics are well-suited for immunoassay applications.
• This technology enables sensitive and direct detection of proteins without labels.