Single-molecule manipulation and detection by WGM-coupled photonic nanojets.

ABSTRACT: Optical manipulation and detection of single molecules, such as biomolecules and bacterial viruses, are crucial in single-molecule mechanics and biosensing. The interaction between light and individual molecules is weak due to the size of biomolecules (≤ 10 nm) being significantly smaller than the wavelength (λ) of light. This limitation results in a reduced optical gradient force and diminished detection sensitivity of light on biomolecules. To overcome this challenge, we propose a single-molecule trapping and sensing method that utilizes whisper-gallery mode (WGM) coupled photonic nanojets (PNJs). Our theoretical analysis demonstrates that a focused beam with a waist radius of λ/6 can be generated by WGM-coupled PNJs. By harnessing this sub-diffraction-limit focused beam, we create a sta

SUBMITTER: Li H 

PROVIDER: S-EPMC12044087 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature