A photoelectrochemical enzyme biosensor based on functionalized hematite microcubes for rutin determination by...

Area of Science:

• Electrochemistry
• Biosensors
• Materials Science

Background:

• Flavonoids, like rutin, are important bioactive compounds with various health benefits.
• Sensitive and selective detection methods for rutin are crucial for food safety and biomedical applications.
• Photoelectrochemical (PEC) biosensors offer advantages in sensitivity and simplicity for detecting biomolecules.

Purpose of the Study:

• To develop a highly sensitive photoelectrochemical biosensing strategy for the detection of the flavonoid rutin.
• To synergize the photoelectrocatalytic properties of hematite (α-Fe2O3) decorated with palladium nanoparticles (PdNPs) and laccase-based biocatalysis.
• To create a novel biosensing platform by integrating α-Fe2O3.PdNPs with a polyphenol oxidase biorecognition element.

Main Methods:

• Fabrication of a photoactive biocomposite using hematite (α-Fe2O3) decorated with palladium nanoparticles (PdNPs).
• Immobilization of a polyphenol oxidase biorecognition element onto the α-Fe2O3.PdNPs platform.
• Detection of rutin via monitoring the cathodic photocurrent generated under visible light irradiation using square-wave voltammetry.
• Evaluation of sensor performance, including sensitivity, selectivity, repeatability, and storage stability.

Main Results:

• The developed PEC biosensor demonstrated a linear response to rutin concentration in the range of 0.008–30.0 × 10⁻⁸ mol L⁻¹.
• An excellent sensitivity of 1.7 μA·(× 10⁻⁸ M⁻¹)·cm⁻² and a low detection limit of 8.4 × 10⁻¹¹ mol L⁻¹ (S/N=3) were achieved.
• The biosensor exhibited good selectivity towards rutin in the presence of various interfering substances and maintained high stability over time (intra-day and inter-day repeatability, long-term storage).

Conclusions:

• The synergistic integration of photoactive α-Fe2O3.PdNPs with laccase-based biocatalysis provides a robust platform for sensitive and selective rutin detection.
• The developed photoelectrochemical biosensor shows great potential for the analysis of rutin in complex matrices.
• This study highlights the efficacy of combining nanomaterials and biocatalysis for advanced bioanalytical device development.