An extensive computational study by researchers from the University of Jyväskylä (Finland) predicted that gold nanoclusters could selectively recognize chiral biomolecules. This property may help in detecting certain diseases directly from a blood sample.
Gold nanoclusters are atomically precise nanostructures with a size of a few nanometers. They contain a metallic gold core, which is protected by a layer of organic ligand molecules. The chemical nature of the ligand molecules determines the solubility of the clusters in different environments and enables the functionality of the organic outer surface of the cluster and interactions with the environment.
Spiral surface can recognize helical biomolecules
The outer surface of gold clusters is often helical, or chiral, just like spiral staircases or the helical structure of DNA. Therefore, they can be expected to bind chiral biomolecules in the environment (such as amino acids or DNA) in different ways, depending on both the chemical structure of the molecules and the direction of the cluster's helix.
- We wanted to test this hypothesis as thoroughly as possible, so we carried out an extensive computational study, says Professor of Computational Nanoscience
Hannu Häkkinen from the University of Jyväskylä, who led the study.
Hundreds of simulations on a supercomputer
The study examined nearly a hundred different combinations of clusters and biomolecules, the atomic structure of which was simulated using molecular dynamics. The binding of biomolecules to clusters in a biological environment and its effect on the chiral optical properties of clusters were studied using electronic structure theory.
- A total of nearly three hundred individual computer runs were needed to ensure the statistical reliability of the results. The study required considerable GPU computing capacity, and the simulations were performed on the joint European LUMI supercomputer managed by the CSC as a Finnish LUMI “Extreme Scale” project, explains Häkkinen.
Clusters selectively recognized biomolecules
The study found clear differences in the interaction between the helical surfaces of different cluster-biomolecule combinations. The interaction turned out to be selective, as only in a few combinations did the biomolecule bind to the cluster surface so strongly that it was able to change the cluster's chiral optical response. The study predicts that this property could be exploited when developing sensors for chiral biomolecules that work in a biological environment. Such sensors could recognize markers related to certain diseases in the blood.
- The results of the simulations are very promising and are based on a simple idea that is easy to test in laboratories. We have already been in contact with experimental groups in our international research network, and we hope that they will be excited to test our predictions in practical laboratory measurements, says Häkkinen.
In addition to Häkkinen, the authors of the publication were Postdoctoral Researcher
Zohreh Fallah, University Researcher
Marìa Francisca Matus and Research Engineer
Sami Malola. The research was published in the prestigious
journal ACS Nano. The research was supported by the Research Council of Finland and the European Research Council's
ERC Advanced Grant project DYNANOINT.
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