(Invited) New Bioinspired Nanomaterials for Biosensing and Cancer Theranostics
Authors: Lin Yuehe , Du Dan (Annie) 
Published: July 2022

Nature is an excellent source of inspiration for the widespread application of science and technology. Researchers learn from biological principles and gradually develop from the earliest direct use of biological materials to the design and development of new biomimetic materials inspired by nature. Therefore, the innovation of bioinspired nanomaterials will enable tremendous advances in biology and biochemistry with biomimetic capabilities, such as biosensing, cell imaging, and drug delivery. In this presentation, I will discuss my group’s recent work on two bioinspired nanomaterials: nano-peptoids and single-atom nanozymes.

The first type of bioinspired materials is a sequence-defined peptide-like materials that can mimic the structure and function of peptides and proteins. Compared with peptides and proteins, peptoids have a high degree of thermal and chemical stability, and are resistant to proteolytic degradation. In addition, due to the lack of intramolecular and intermolecular backbone hydrogen bond donors, it is possible to precisely control the peptoid and peptoid-substrate interactions, leading to bio-inspired synthesis of nanomaterials with a layered structure. As a peptide mimic, the peptoids has biocompatibility, non-toxicity and sequence-specific heteropolymers. Nano-peptoids can be synthesized with polar and hydrophobic monomers and have the following advantages: They can be easily processed into desired shapes (e.g. dendritic, sheets, tubes and vesicles), and the size range is 2-100 nm to enhance cell targeting and uptake. The application of nano-peptoids in cell imaging and cancer theranostics will be discussed.

Another type of bioinspired nanomaterials with enzyme-like properties is single-atom nanoenzymes. As a biocatalyst, natural enzymes have the ability to accelerate various reaction rates with extremely high activity and selectivity under mild conditions. However, due to the temperature and pH-related denaturation of proteins and the possibility of contamination by bacteria or other reagents, the shelf life of natural enzymes is limited or uncertain, and their purification and production costs are high. Therefore, natural enzymes must narrow the range of conditions under which they can be used, limiting their further applications in biosensing and biomedicine. R Recent research has focused on the rational design of nanomaterials with inherent enzyme-like catalytic properties (for example, oxidase, peroxidase, catalase, superoxide dismutase, and so on) and exploration of their applications in various fields. Although much progress has been made, the development of nanozymes is still hampered by several challenges. Catalytic activity and substrate selectivity are the two most important issues that need to be resolved to allow the technology to reach full maturity. Therefore, rational design and tuning of nanomaterials is highly desirable for the development of novel enzyme-mimic nanomaterials with precise catalytic sites. We have developed various Fe-N-C based single atomic site catalysts which have similar structure with active site of peroxidase. These atomically-dispersed Fe-N-C materials have enzyme-like properties, therefore they are classified as single-atom nanozymes. Together with their abundantly exposed active sites and specific structures, these single atomic nanozymes have great potential for the enhancement of biocatalytic activity and selectivity in biosensing.

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Zhu, S. Fu, Q. Shi, D. Du, Y. Lin. Single-Atom Electrocatalysts. Angew. Chem. Int. Ed. 2017, 56, 13944-13960.

Cheng, J. Li, D. Liu, Y. Lin, D. Du. Single-Atom Nanozyme Based on Nanoengineered Fe-N-C Catalyst with Superior Peroxidase-Like Activity for Ultrasensitive Bioassays. Small, 2019, 1901485.

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Jiao, W. Xu, Y. Wu, H. Yan, W. Gu, D. Du, Y Lin, C. Zhu, Single-atom Catalysts Boost Signal Amplification for Biosensing. Chemical Society Reviews 2021, 50, 750-765

Luo, Y. Song, M. Wang, T. Jian, S. Ding, P. Mu, Z. Liao, Q. Shi, X. Cai, H. Jin, D. Du, W. Dong, C. Chen, Y. Lin. Bioinspired Peptoid Nanotubes for Targeted Tumor Cell Imaging and Chemo-Photodynamic Therapy. Small 2019, 1902485.

Song, M. Wang, S. Akkineni, W. Yang, J.J. Hettige, H. Jin, Z. Liao, P. Mu, F. Yan, M. Baer, J. De Yoreo, D. Du, Y. Lin, C. Chen. Highly Bright and Photostable Two-Dimensional Nanomaterials Assembled from Sequence-Defined Peptoids. ACS Materials Letters
2021, 3, 420-427.

Cai, M. Wang, P. Mu, T. Jian, D. Liu, S. Ding, Y. Luo, D. Du, Y. Song, C. Chen, Y. Lin. Sequence-Defined Nanotubes Assembled from IR780-Conjugated Peptoids for Chemophototherapy of Malignant Glioma. Research 2021, Article ID 9861384.