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Published on: July 21, 2023
Electrocatalytic Amplification of Single Nanoparticle Collisions Using DNA-Modified Surfaces
Timothy M Alligrant1, Radhika Dasari1, Keith J Stevenson1
1Department of Chemistry and Center for Nano- and Molecular Science and Technology, The University of Texas at Austin , 105 E. 24th St., Stop A5300, Austin, Texas 78712-0165 United States.
DNA modification on platinum nanoparticles (PtNPs) impacts electrocatalytic amplification (ECA) signals during collisions with ultramicroelectrodes (UMEs). High DNA surface concentrations on PtNPs block catalytic sites, reducing ECA signals, while naked PtNPs interact effectively with DNA-modified UMEs.
Area of Science:
- Nanomaterials Science
- Electrochemistry
- Biosensing
Background:
- Electrocatalytic amplification (ECA) is a phenomenon observed during nanoparticle-electrode collisions.
- ECA has potential applications in sensitive biosensing.
- Understanding surface modifications is crucial for optimizing ECA.
Purpose of the Study:
- To investigate the effect of DNA modification on PtNPs and UME surfaces on ECA signals.
- To explore the role of DNA length and surface concentration in modulating ECA.
- To assess the potential for DNA-modified PtNPs in biosensing applications.
Main Methods:
- Studied collisions between naked PtNPs and DNA-modified Au/Hg UMEs.
- Investigated collisions between DNA-modified PtNPs and naked Au/Hg UMEs.
- Analyzed ECA signals generated during the catalytic oxidation of hydrazine (N2H4).
Main Results:
- Immobilizing ssDNA on UME surfaces had minimal impact on ECA signal magnitude or frequency.
- Increasing ssDNA surface concentration on PtNPs led to decreased ECA signal magnitude and frequency.
- This inhibitory effect was more pronounced with longer ssDNA (25-mer).
- Naked PtNPs showed effective electron transfer with sparsely DNA-coated UMEs.
Conclusions:
- High surface concentration of ssDNA on PtNPs can block active sites, hindering electrocatalytic activity.
- DNA modification on PtNPs can be used to tune ECA signals.
- The findings provide insights into the design of nanoparticle-electrode interfaces for biosensing.
