Single Molecule Profiling of Molecular Recognition at a Model Electrochemical Biosensor

Area of Science:

• * Bioanalytical Chemistry
• * Surface Science
• * Nanotechnology

Background:

• * Biosensor performance relies on the precise spatial arrangement of probe and target molecules at the biointerface.
• * Current understanding of single-molecule spatial patterns on functional biosensors is limited, hindering rational design.
• * Investigating molecular arrangements is key to optimizing interfacial molecular recognition.

Purpose of the Study:

• * To map and characterize the spatial patterns of individual probe and target molecules on a functioning electrochemical DNA sensor.
• * To analyze single-molecule spatial distributions using high-resolution atomic force microscopy and spatial statistics.
• * To elucidate the relationship between molecular spatial organization and biosensor performance.

Main Methods:

• * High-resolution atomic force microscopy (AFM) for nanoscale imaging of biosensor surfaces.
• * Spatial statistical analysis to quantify single-molecule patterns and distributions.
• * Characterization of hybridization events on an electrochemical DNA sensor.

Main Results:

• * Observed heterogeneous spatiotemporal patterns in hairpin probe hybridization on the sensor surface.
• * Demonstrated that target capture clustering suggests proximity-enhanced hybridization, with optimal enhancement around 10 nm.
• * Revealed a complex interplay between probe spatial organization, probe conformation, and target binding.

Conclusions:

• * Nanoscale spatial organization of probe molecules significantly impacts biosensor performance.
• * Understanding molecular-level spatial arrangements allows for tailored biosensor surface design.
• * This knowledge can lead to enhanced sensitivity and reproducibility in biosensor applications.