Electromagnetic manipulation of sub-500 Da biomolecules

TL;DR

This paper presents a novel device combining dielectrophoresis and plasmonic tweezers to efficiently trap and sense biomolecules as small as a few hundred Daltons, enabling advanced nanoscale biosensing.

Contribution

The work introduces a hybrid trapping device that enhances the manipulation and sensing of small biomolecules, extending capabilities to molecules relevant for life sciences.

Findings

Successful trapping of biomolecules as small as a few hundred Daltons.

Enhanced surface Raman scattering signals for small biomolecules.

Potential applications in single-molecule biosensing and quantum science.

Abstract

The manipulation of nanoscale matter has the potential to revolutionize a variety of fields across nanoscience and technology. Here, we demonstrate experimentally and characterize numerically a device that combines the benefits of dielectrophoresis (DEP) - long-range and strong trapping forces - with those of plasmonic tweezers - high sensitivities - to achieve a remarkable efficiency in the trapping and sensing of metallic nanoparticles and biomolecules. In particular, we show the DEP trapping and surface enhanced Raman scattering characterization of bovine serum albumin and Rhodamine B, thus extending the applications of tweezing devices to molecules having masses of only a few hundreds of Da. This range covers virtually any molecule relevant for life, from tiny oligopeptides to large proteins. This pushes our manipulation capabilities deep into the realms of efficient single-molecule biosensing and quantum science, providing a powerful platform to probe matter at the nanoscale.