Fluorescence excitation enhancement by waveguiding nanowires
Journal article, 2023

The optical properties of vertical semiconductor nanowires can allow an enhancement of fluorescence from surface-bound fluorophores, a feature proven useful in biosensing. One of the contributing factors to the fluorescence enhancement is thought to be the local increase of the incident excitation light intensity in the vicinity of the nanowire surface, where fluorophores are located. However, this effect has not been experimentally studied in detail to date. Here, we quantify the excitation enhancement of fluorophores bound to a semiconductor nanowire surface by combining modelling with measurements of fluorescence photobleaching rate, indicative of the excitation light intensity, using epitaxially grown GaP nanowires. We study the excitation enhancement for nanowires with a diameter of 50-250 nm and show that excitation enhancement reaches a maximum for certain diameters, depending on the excitation wavelength. Furthermore, we find that the excitation enhancement decreases rapidly within tens of nanometers from the nanowire sidewall. The results can be used to design nanowire-based optical systems with exceptional sensitivities for bioanalytical applications.

Author

Ivan N. Unksov

Lund University

Nicklas Anttu

Åbo Akademi

Damiano Verardo

Lund University

Medicon Village

Fredrik Höök

Chalmers, Physics, Nano and Biophysics

Christelle N. Prinz

Lund University

Heiner Linke

Lund University

Nanoscale Advances

25160230 (eISSN)

Vol. 5 6 1760-1766

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Condensed Matter Physics

DOI

10.1039/d2na00749e

More information

Latest update

1/3/2024 9