Phase Behavior and Selectivity of DNA-linked Nanoparticle Assemblies

TL;DR

This paper introduces a model explaining the phase behavior of DNA-linked nanoparticle assemblies, predicting how factors like DNA coverage and salt concentration influence phase separation, aiding mutation detection.

Contribution

The study presents a novel model linking DNA sequence interactions to the macroscopic phase behavior of nanoparticle assemblies, enhancing understanding and detection methods.

Findings

Phase-separation temperature increases with DNA coverage.

Demixing temperature rises logarithmically with salt concentration.

Model predicts a strategy for mutation detection based on phase behavior.

Abstract

We propose a model that can account for the experimentally observed phase behavior of DNA-nanoparticle assemblies (R. Jin et al., JACS 125, 1643 (2003); T. A. Taton et al., Science 289, 1757 (2000)). The binding of DNA-coated nano-particles by dissolved DNA linker can be described by exploiting an analogy with quantum particles obeying fractional statistics. In accordance with experimental findings, we predict that the phase-separation temperature of the nano-colloids increases with the DNA coverage of the colloidal surface. Upon the addition of salt, the demixing temperature increases logarithmically with the salt concentration. Our analysis suggests an experimental strategy to map microscopic DNA sequences onto the macroscopic phase behavior of the DNA-nanoparticle solutions. Such an approach should enhance the efficiency of methods to detect (single) mutations in specific DNA sequences.