The Role of Nanoparticle Design in Determining Analytical Performance of Lateral Flow Immunoassays

Nano Lett. 2017 Dec 13;17(12):7207-7212. doi: 10.1021/acs.nanolett.7b02302. Epub 2017 Nov 15.


Rapid, simple, and cost-effective diagnostics are needed to improve healthcare at the point of care (POC). However, the most widely used POC diagnostic, the lateral flow immunoassay (LFA), is ∼1000-times less sensitive and has a smaller analytical range than laboratory tests, requiring a confirmatory test to establish truly negative results. Here, a rational and systematic strategy is used to design the LFA contrast label (i.e., gold nanoparticles) to improve the analytical sensitivity, analytical detection range, and antigen quantification of LFAs. Specifically, we discovered that the size (30, 60, or 100 nm) of the gold nanoparticles is a main contributor to the LFA analytical performance through both the degree of receptor interaction and the ultimate visual or thermal contrast signals. Using the optimal LFA design, we demonstrated the ability to improve the analytical sensitivity by 256-fold and expand the analytical detection range from 3 log10 to 6 log10 for diagnosing patients with inflammatory conditions by measuring C-reactive protein. This work demonstrates that, with appropriate design of the contrast label, a simple and commonly used diagnostic technology can compete with more expensive state-of-the-art laboratory tests.

Keywords: C-reactive protein; Gold nanoparticles; immunoassay; size dependent; thermal contrast.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies / immunology
  • C-Reactive Protein / analysis
  • C-Reactive Protein / immunology
  • Diffusion
  • Gold / chemistry*
  • Humans
  • Immunoassay / methods*
  • Inflammation / diagnosis
  • Kinetics
  • Limit of Detection
  • Metal Nanoparticles / chemistry*
  • Particle Size
  • Point-of-Care Testing
  • Temperature


  • Antibodies
  • Gold
  • C-Reactive Protein