posted on 2023-11-24, 00:59authored bySu-Heon Kwak, Dae Gwin Jeong, Hyun Kyong Shon, Dong-Ho Kim, Tae Geol Lee, Jung-Sub Wi, Hee-Kyung Na
The need exists for biosensing technologies
capable of sensitively
and accurately detecting various biomarkers. In response, the development
of nanozymes is actively underway; they have advantages in stability,
cost, performance, and functionalization over natural enzymes commonly
used for signal amplification in sensing technologies. However, the
performance of nanozymes is interdependent with factors such as shape,
size, and surface functional moiety, making it challenging to perform
quantitative performance comparisons based on the nanozyme material.
In this study, we propose a physical synthetic approach to fabricate
double-layered bimetallic nanozymes with identical shapes, sizes,
and surfaces but different material compositions. These Janus nanozymes
consist of a nanozymatic layer responsible for catalytic activity
and a gold layer responsible for quantification and efficient surface
modification. Based on their identical physicochemical properties,
the synthesized double-layered bimetallic nanozymes allow, for the
first time, a quantitative comparison of nanozymatic activities in
terms of various kinetic parameters. We compared several candidates
and found that the Ir–Au nanozyme exhibited the best performance.
Subsequently, we applied this nanozyme to detect neutralizing antibodies
against SARS-CoV-2 based on a surrogate virus neutralization test.
The results demonstrated a limit of detection as low as 2 pg/mL and
selectivity specifically toward MERS-CoV. The performance of this
assay was further validated using vaccinated samples, demonstrating
the potential of our approach as a cost-effective, rapid, and sensitive
diagnostic tool for neutralizing antibody detection against viruses
such as SARS-CoV-2.