Natural Enzyme Alternatives? Nanomaterials with enzyme-mimicking activities played critical roles in biomedical analysis and beyond
Can the delicate natural enzymes be replaced by more robust nanomaterials?
The answer is yes according to the researchers gathered at Boston in the 256th ACS National Meeting & Exposition.
Natural enzymes, such as horseradish peroxidase (HRP), are highly efficient and specific catalysts with delicate three dimensional structures. Most of enzymes are proteins, which not only cost highly but are also susceptible to denaturation under harsh conditions. Researchers have long searched for alternatives to natural enzymes, called artificial enzymes, to address these issues. Along with the development of nanoscience and nanotechnology, scientists have showed that nanomaterials could mimic natural enzymes. These enzyme-like functional nanomaterials are collectively called as “nanozymes”.
Nanozymes have received great attentions recently because of their advantages over natural enzymes and even conventional enzyme mimics. Nanozymes have been explored for a wide range of applications. Particularly, they have been used for varieties of analytical applications, ranging from bioactive small molecule detection and immunoassays to bioimaging and cancer diagnosis. In the “Nanozymes for Bioanalysis” symposium at the 256th ACS National Meeting & Exposition, organized by Professor Hui Wei from Nanjing University, researchers around the world gathered together and discussed the various aspects of bioanalysis applications of nanozymes.
“I really appreciated ACS to provide such a platform to invite the researchers in the field to discuss the recent progress of nanozymes in bioanalysis,” Wei said. “In the symposium, the speakers talked the detection of important targets (such as cancer biomarkers, cardiovascular diseases biomarkers, HIV biomarkers, biofilms, heavy metal ions, anionic ions, bioactive small molecules, and virus) with nanozymes-enabled platforms (such as lateral flow immunoassay and sensor arrays). They also presented their recent progress in the nanozyme activity modulation, the neuroprotection by scavenging ROS, and even the C-H activation by nanozymes.”
One of the unmet challenges is the specificity of the currently nanozymes developed. Professor Juewen Liu from University of Waterloo showed by coating a nanozyme core with an imprinted polymer, high selectivity towards a given target could be achieved. To address the intrinsic specificity of a nanozyme, Wei and collaborators demonstrated that by doping carbon nanomaterials (such as graphene and mesoporous carbon) with nitrogen, highly specific peroxidase mimics could be developed. Such a specificity could minimize the interference of other enzyme-like activities, such as catalase-like activity, which would otherwise consume the hydrogen peroxide and thus compete against the peroxidase-like activity. With the N-doped graphene as a peroxidase mimic, Wei et al. showed the detection of hydrogen peroxide with the nanozyme was improved when compared with multi-enzyme mimics.
“Encouraged by the success of this symposium,” Noted by Wei, “I plan to organize another symposium in the next ACS meeting.”