DNA Sensing with Whispering Gallery Mode Microlasers

TL;DR

This paper introduces a novel DNA sensing platform using whispering gallery mode microlasers that enables real-time, label-free detection of DNA interactions with enhanced sensitivity through gold nanoparticles and offers potential for diagnostics and drug delivery.

Contribution

The study presents a new WGM microlaser-based platform for DNA detection that improves sensitivity and eliminates secondary labeling, with applications in diagnostics and controlled release.

Findings

Spectral shifts correlate with DNA hybridization and structural changes.

Gold nanoparticles significantly enhance sensing sensitivity.

The system can be used for multiplexed detection and in vivo applications.

Abstract

Nucleic acid sensing is crucial for advancing diagnostics, therapeutic monitoring and molecu-lar biology research, by enabling the precise identification of DNA and RNA interactions. Here, we present an innovative sensing platform based on DNA-functionalized whispering gallery mode (WGM) microlasers. By correlating spectral shifts in laser emission to changes in refractive index, we demonstrate real-time detection of DNA hybridization and structural changes. The addition of gold nanoparticles to the DNA strands significantly enhances sensi-tivity, and labeling exclusively the sensing strand or a hairpin strand eliminates the need for secondary labeling of the target strand. We further show that ionic strength influences DNA compactness, and we introduce a hairpin-based system as a dual-purpose sensor and con-trolled release mechanism for potential drug delivery. This versatile WGM-based platform of-fers promise for sequence-specific nucleic acid sensing, multiplexed detection, and in vivo ap-plications in diagnostics and cellular research.