Enhanced Refractive Index Sensitivity of Linearly Assembled Gold Nanoantennae for Biosensing Applications

Research output: Contribution to journal › Research article › Contributed › peer-review

Contributors

  • Taufhik Hossain Tonmoy - , Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Author)
  • Sezer Seçkin - , Leibniz Institute of Polymer Research Dresden (Author)
  • Marisa Hoffmann - , Leibniz Institute of Polymer Research Dresden (Author)
  • Isli Çela - , Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Author)
  • Gyusang Yi - , Leibniz Institute of Polymer Research Dresden (Author)
  • Ahmed Alsadig - , Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Author)
  • Swagato Sarkar - , Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Leibniz Institute of Polymer Research Dresden (Author)
  • Christian Rossner - , Leibniz Institute of Polymer Research Dresden, TUD Dresden University of Technology, University of Chemistry and Technology, Prague (Author)
  • Tobias A.F. König - , Leibniz Institute of Polymer Research Dresden, TUD Dresden University of Technology, Center for Advancing Electronics Dresden (cfaed) (Author)
  • Andreas Fery - , Leibniz Institute of Polymer Research Dresden (Author)
  • Larysa Baraban - , Else Kröner Fresenius Center for Digital Health, Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Author)

Abstract

Compared to individual nanoparticles, supracolloidal structures offer unique plasmonic properties with enhanced susceptibility to variations in the local refractive index. In this study, we report the template-assisted fabrication of large-scale (ca. 1 cm2) linear periodic assemblies of AuNPs and demonstrate their polarization-dependent biosensing performance at the proof-of-concept level. We explore two complementary approaches for template fabrication: i) laser interference lithography (LIL), offering high-fidelity patterns over moderate areas, and ii) wrinkle-assisted patterning, a more scalable and cost-effective strategy. Despite structural differences, both approaches yield comparable sensing performances. This demonstrates the broad potential utility of the developed biosensing platform. First, sensors are characterized through varying concentrations of glycerol/water mixtures with known refractive indices. Next, as a proof-of-concept application, we perform biofunctionalization and detection of the antibody for Tumor Necrosis Factor-Alpha (TNF-α). TNF-α is a pro-inflammatory cytokine that plays a multifaceted role in cancer prognosis. The shifts in plasmonic resonance peaks of the AuNP assemblies are quantified using polarized-light vis-NIR spectrometry during various stages of the functionalization and detection process. The experimental results reveal a pronounced polarization-dependent plasmonic resonance peak shift (Δλ). Overall, a signal enhancement of up to 5-fold is observed in the longitudinal mode over the transversal case, a feature consistently achieved across both LIL and wrinkled templates. These findings present an innovative supracolloidal structuring approach for the development and scalable production of highly sensitive, plasmonic biochips.

Details

Original languageEnglish
Article numbere10159
JournalSmall
Volume22
Issue number9
Early online date23 Dec 2025
Publication statusPublished - 12 Feb 2026
Peer-reviewedYes

External IDs

ORCID /0000-0003-1010-2791/work/201625226
PubMed 41432145

Keywords

Sustainable Development Goals

Keywords

  • biosensors, gold nanoantennae, localized surface plasmon resonance, refractive index sensitivity, supracolloidal assemblies, Tumor Necrosis Factor Alpha (TNF-α)