Events

Public defence in Biomedical Engineering, M.Sc. Yike Huang

Title of the doctoral thesis: DNA origami-based reconfigurable chiral plasmonic nanodevices for analytical applications

Opponent: Professor Friedrich Simmel, Technical University of Munich, Germany
Custos: Associate Professor Anton Kuzyk, Aalto University School of Science, Department of Neuroscience and Biomedical Engineering

The defence will be organized on campus.

The doctoral thesis will be publicly displayed 10 days before the defence in the publication archive of Aalto University.

Electronic doctoral thesis

Public defence announcement:

The idea that the unique molecular recognition properties of DNA molecules might also be used for materials’ fabrication emerged in early 1980’s. The DNA origami, which folds a long ‘scaffold’ DNA into a desired pattern with the assistance of hundreds of short ‘staple strands’, allows the construction of templates for assembly of various hetero element components with nanometre precision. By accurately attaching metal nanoparticles to DNA origami templates, controlled coupling of plasmonic resonances is enabled. In the coupled plasmonics system, optical responses are sensitive to the relative positioning of the metal nanoparticles. Particularly, the circular dichroism (CD) responses can be readily correlated with the structural configurations of the chiral plasmonic assemblies. With rational design, CD signals can be altered by molecular stimuli through configurational change. To realize the control of CD signals with target molecules, we utilized aptamers, which are single-stranded nucleic acid strands that specifically bind to target molecules with high affinities.

By combining aptamers with DNA origami-based reconfigurable chiral plasmonic assemblies, we developed biosensors that allowed selective and sensitive detection of biomolecules. The significance of biosensing has been highlighted by the recent global pandemic of SARS-CoV-2. Besides health care, biosensors also play crucial roles in food safety, environmental monitoring, and forensics. The CD-based biosensors can perform even in strongly light-absorbing environments, demonstrating that DNA origami-based reconfigurable chiral plasmonic assemblies as promising alternative optical reporters compared to traditional fluorescent probes.

Through developing thermodynamic and kinetic models, we also achieved reliable characterization of versatile aptamers, which has remained problematic as the generalizable approaches to measuring affinities and specificities of aptamers are limited. The research results may address the discrepancy in the aptamer characterization and bridge the gap between upstream-selection and downstream-application of the aptamer field.

Contact details of the doctoral student: [email protected], +358503027390

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