Ionic-Liquid-Stabilized TiO₂ Nanostructures: A Platform for Detection of Hydrogen Peroxide

Area of Science:

• Nanomaterials Science
• Analytical Chemistry
• Biomedical Sensing

Background:

• Hydrogen peroxide (H2O2) is a crucial signaling molecule, but its excess causes oxidative stress and cancer.
• Developing accurate and sensitive methods for H2O2 detection is vital for early cancer diagnosis.

Purpose of the Study:

• To synthesize and characterize ionic liquid-capped TiO2 nanoparticles (TiO2/IL).
• To develop a novel colorimetric sensing probe for H2O2 detection using TiO2/IL NPs.
• To evaluate the sensor's performance and applicability in biological samples.

Main Methods:

• Facile hydrothermal synthesis of TiO2 nanostructures.
• Functionalization of TiO2 NPs with 1-H-3-methylimidazolium acetate ionic liquid.
• Colorimetric detection of H2O2 using TiO2/IL NPs and TMB dye.
• Characterization via FTIR, XRD, SEM, EDX, TGA, and Raman spectroscopy.
• Optimization of sensing parameters (pH, time, concentration).

Main Results:

• Successful synthesis and characterization of TiO2/IL NPs.
• The TiO2/IL/TMB system exhibited a distinct color change upon H2O2 presence.
• Achieved a low limit of detection (8.61 × 10⁻⁸ M) and high sensitivity (2.86 × 10⁻⁷ M).
• Demonstrated excellent linearity (R² = 0.999) over a wide range (1 × 10⁻⁹–3.6 × 10⁻⁷ M) with a 4-min incubation time.
• Showed no interference from coexisting species and effective application in urine samples of cancer patients.

Conclusions:

• The developed TiO2/IL-based colorimetric sensor is highly sensitive, selective, and rapid for H2O2 detection.
• This sensor holds promise for non-invasive H2O2 monitoring in clinical diagnostics, particularly for cancer detection.
• The functionalization with ionic liquids enhances nanoparticle dispersion and sensor performance.