Publications by authors named "Adrian Jan Grzedowski"
Decorating a gold surface with molecular-level control over the positioning of DNA probes was demonstrated using a self-assembled monolayer (SAM) of wireframe DNA nanocube structures. The DNA nanocubes were specifically adsorbed and oriented using thiol-modified DNA on one face of the cube. The DNA nanocube SAM had a uniform coverage over the gold single crystal bead electrode with a separation of 20-30 nm measured by AFM.
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- Mixed DNA self-assembled monolayers (SAMs) were created on gold beads using specific labeling fluorophores, allowing researchers to study their local environments through Förster resonance energy transfer (FRET).
- The FRET signal varied based on the surface density of DNA and the ratio of the fluorophores used, providing insights into the arrangement of the DNA on the surface and how it affects hybridization rates.
- Analysis showed that lower coverage regions of DNA SAMs hybridized significantly faster than higher coverage areas, and FRET intensity could be optimized by adjusting the surface coverage and fluorophore ratios without affecting hybridization speed.
Article Synopsis
- Interfaces modified by molecular monolayers are complex to study in real time, necessitating innovative methods that combine electrochemical and optical techniques.
- The study introduces a new method that uses redox electrochemistry to modulate fluorescence intensity for detecting DNA hybridization and assessing surface uniformity.
- Key factors affecting fluorescence included the oxidation state of methylene blue (MB), DNA surface density, the ratio of MB to fluorophore (AlexaFluor488), and the local environment, highlighting the technique's effectiveness for surface analysis and hybridization detection.
The formation of defined surfaces consisting of photosynthetic reaction centers (RCs) in biohybrid solar cells is challenging. Here, we start with the production of engineered RCs for oriented binding. RCs are deposited onto gold electrodes, and 6-mercapto-1-hexanol (MCH) is used to displace multilayers and non-specifically adsorbed RCs.
View Article and Find Full Text PDFThe use of biomacromolecules is a nascent development in clean alternative energies. In applications of biosensors and biophotovoltaic devices, the bacterial photosynthetic reaction center (RC) is a protein-pigment complex that has been commonly interfaced with electrodes, in large part to take advantage of the long-lived and high efficiency of charge separation. We investigated assemblies of RCs on an electrode that range from monolayer to multilayers by measuring the photocurrent produced when illuminated by an intensity-modulated excitation light source.
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