p-d Orbital Hybridization-Engineered PdSn Nanozymes for a Sensitive Immunoassay

Area of Science:

• Nanomaterials Science
• Biotechnology
• Analytical Chemistry

Background:

• Nanozymes with peroxidase-like activity are used in colorimetric biosensing.
• Their catalytic activity and specificity are often inferior to natural enzymes, limiting biosensing accuracy and sensitivity.

Purpose of the Study:

• To design palladium-tin (PdSn) nanozymes with selectively enhanced peroxidase-like activity.
• To improve the sensitivity and accuracy of colorimetric immunoassays using these novel nanozymes.

Main Methods:

• Synthesis of PdSn nanozymes and characterization of their peroxidase-like activity.
• Theoretical calculations to understand the electronic structure and catalytic mechanism.
• Development of a nanozyme-linked immunosorbent assay (ELISA) for prostate-specific antigen (PSA) detection.

Main Results:

• PdSn nanozymes exhibited significantly higher peroxidase-like activity compared to Pd nanozymes.
• Theoretical analysis indicated that PdSn's p-d orbital hybridization enhances hydrogen peroxide (H2O2) adsorption and activation.
• The developed nanozyme-ELISA achieved sensitive and accurate PSA detection with a low limit of 1.696 pg mL⁻¹.

Conclusions:

• PdSn nanozymes offer a promising platform for enhancing colorimetric biosensing performance.
• This approach provides a sensitive and accurate method for detecting biomarkers like PSA in clinical diagnostics.