A research group led by Dr. WANG Shu from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has developed an innovative immunochromatographic technique based on silicon-based bimetallic nanozymes (Si@Au/Ir). This breakthrough enables high-sensitivity, multi-functional, and multi-channel detection of environmental pollutants. 

The research results were published in Chemical Engineering Journal.

Lateral flow immunoassay (LFA) is a popular method for rapid on-site detection of harmful substances, offering portable and accurate screening. However, traditional LFA relies on colorimetric signals, which limit its detection speed and sensitivity. This has driven researchers to explore new signal tags for enhanced performance.

In this study, by employing precise electrostatic adsorption and self-assembly techniques, the researchers integrated gold/iridium (Au/Ir) bimetallic nanoparticles onto the surface of silicon spheres, creating Si@Au/Ir nanozyme signal tags with uniform distribution, excellent stability, and exceptional catalytic efficiency. 

They also coupled target-specific antibodies to the surface of the signal tags via amidation reactions, achieving a high level of specificity in binding, akin to a "lock and key" mechanism.

The resulting detection platform enables on-site, rapid, and simultaneous detection of multiple environmental hazards, including cadmium ions (Cd²⁺), clenbuterol hydrochloride (CLE), and gentamicin (GM). 

"Our method offers a more efficient solution for pollutant detection," said Prf. WANG Shu. "It plays a key role in environmental and food safety."

Bimetallic composite nanoenzyme tags (Si@Au/Ir) and the construction of three highly sensitive combined test strips for environmental hazard factor detection. (Image by ZHENG Shuai)