Thermal-annealing-regulated plasmonic enhanced fluorescence platform enables accurate detection of antigen/antibody against infectious diseases

Plasmonic enhanced fluorescence (PEF) technology is a powerful strategy to improve the sensitivity of immunofluorescence microarrays (IFMA), however, current approaches to constructing PEF platforms are either expensive/time-consuming or reliant on specialized instruments. Here, we develop a completely alternative approach relying on a two-step protocol that includes the self-assembly of gold nanoparticles (GNPs) at the water oil interface and subsequent annealing-assisted regulation of gold nanogap. Our optimized thermal-annealing GNPs (TA-GNP) platform generates adequate hot spots, and thus produces high density electromagnetic coupling, eventually enabling 240 -fold fluorescence enhancement of probed dyes in the near-infrared region, For clinical detection of human samples, TA-GNP provides super-high sensitivity and low detection limits for both hepatitis B surface antigen and SARS-CoV-2 binding antibody, coupled with a much-improved detection dynamic range up to six orders of magnitude. Wth fast detection, high sensitivity, and low detection limit, TA-GNP could not only substantially improve the outcomes of IFMA-based precision medicine but also find applications in fields of proteomic research and clinical pathology.

Automated summary

This article introduces an improved method for enhancing fluorescence using plasmonic enhanced fluorescence (PEF) technology. By self-assembling gold nanoparticles (GNPs) and subsequent annealing-assisted regulation, the method achieves fluorescence enhancement and high density electromagnetic coupling in the near-infrared region. The method has high sensitivity and low detection limit, making it valuable for clinical detection and disease diagnosis.