Bimetallic Single-Atom Nanozyme-Based Electrochemical-Photothermal Dual-Function Portable Immunoassay with Smartphone...

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• Accurate detection of human epidermal growth factor receptor 2 (HER2) is critical for breast cancer diagnosis and prognosis.
• Existing detection methods may face limitations in sensitivity, speed, or environmental impact.
• Single-atom nanozymes offer unique catalytic properties for biosensing applications.

Purpose of the Study:

• To develop a novel nanozyme-based bifunctional immunoassay for sensitive HER2 detection.
• To investigate the catalytic activity of iron-manganese N-doped carbon single-atom catalysts (FeMn-NC_etch/SAC) in generating hydroxyl radicals.
• To establish a portable electrochemical-photothermal detection platform for reliable HER2 quantification.

Main Methods:

• Synthesis and characterization of FeMn-NC_etch/SAC bimetallic nanozymes.
• Design of a portable electrochemical-photothermal bifunctional immunoassay platform.
• Utilizing glucose oxidase (GOx) for H₂O₂ generation and FeMn-NC_etch/SAC for catalyzing TMB oxidation, converting colorimetric signals to electrical and photothermal signals.

Main Results:

• FeMn-NC_etch/SAC demonstrated efficient peroxidase-like activity for hydroxyl radical generation.
• The bifunctional immunoassay achieved sensitive HER2 detection with photothermal LOD of 7.5 pg mL^-1 (linear range 0.01–2.0 ng mL^-1) and electrochemical LOD of 3.9 pg mL^-1 (linear range 0.01–10 ng mL^-1).
• The developed platform showed reliable and accurate HER2 detection, avoiding environmental interference.

Conclusions:

• Single-atom bimetallic nanozymes exhibit unique advantages for biosensing.
• The developed electrochemical-photothermal bifunctional immunoassay provides a sensitive, accurate, and portable method for HER2 detection.
• This strategy offers significant potential for clinical breast cancer diagnosis.