Fluorescence-free bis(dithiolene)nickel dyes for surface-enhanced resonance Raman imaging in the second near-infrared window

Biomaterials. 2023 Sep:300:122211. doi: 10.1016/j.biomaterials.2023.122211. Epub 2023 Jun 23.

Abstract

Second near-infrared window (NIR-II, 1000-1700 nm) imaging is one of the foremost optical imaging techniques. However, surface-enhanced Raman scattering (SERS)-based research in this optical region remains in its infancy, mainly because of a lack of suitable NIR-II Raman reporters. Herein, we report the first example of a nickel dithiolene complex as a NIR-II resonance Raman reporter with intense long wavelength absorption (ε = 9.58 × 104 m-1 cm-1 at 1007 nm), fluorescence-free features and ultrahigh affinity to noble metal surfaces with its eight sulfur atoms. Surface-enhanced resonance Raman scattering nanoprobes constructed with such reporters enable high contrast and highly photostable lymph node imaging far superior to that possible with existing NIR-I and NIR-II SERS nanoprobes. The developed NIR-II nanoprobes allow deep optical penetration (8 mm) as well as in vivo SERS detection of deep-seated microtumors in mice.

Keywords: Bioimaging; Bis(dithiolene)nickel dyes; Deep penetration; SERS; Second near-infrared.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Coloring Agents*
  • Lymph Nodes
  • Mice
  • Nickel*
  • Optical Imaging
  • Sulfur

Substances

  • Nickel
  • Coloring Agents
  • Sulfur