Dual detection of COVID-19 antigens and antibodies using nanoscale fluorescent plasmonic substrates

Abstract

There is a continuing need for biosensors that can be used in the diagnosis of COVID-19 infection and to measure a subject’s immune response to the virus itself (SARS-CoV-2). In this study, grating-coupled fluorescent plasmonic (GC-FP)-based detection of SARS-CoV-2 antigens was coupled with antibody detection to yield a dual-mode detection assay. Pairs of capture and detection antibodies were screened for direct detection of the SARS-CoV-2 nucleocapsid (Nuc) antigen, which were then combined with an existing GC-FP antibody detection assay. Nuc could be detected as low as 1 µg/mL concentrations, while antibodies were detectable to 50 ng/mL. The dual detection assay was tested by adding purified Nuc antigen to serum from a polymerase chain reaction (PCR)-positive COVID-19-infected individual. Using this sample, co-detection of Nuc antigen and anti-spike protein antibodies was successfully performed on a single GC-FP chip. Total assay time was 1 h, making this the first known example of rapid dual antibody and antigen detection on the same biosensor chip.

RPA-CRISPR/Cas12a-LFA combined with a digital visualization instrument to detect Toxoplasma gondii in stray dogs and cats in Zhejiang province, China

“…Serological testing is a common tool to detect T. gondii infection; however, it has the drawback of a longer window period. Moreover, traditional amplification methods, such as PCR and qPCR, are time-consuming, taking up to 2 h or even longer, requiring thermal cycling, and relying on well-established laboratories with sophisticated facilities or well-trained operators ( 35 ). Although LAMP is a thermostatic amplification method, its primer design is complex and is prone to aerosol contamination.…”

The therapeutic bionanoscience interface

“…In this thematic issue, there are six mini-reviews and two original research articles targeting, toxicology, 1 pathogen and exosome detection, 2,3 spinal cord injury, 4 tissue scaffolds, 5 molecular barcoding, 6 RNA biology, 7 and bio-hybrid electronic devices 8 that bridge biology with nanotechnology and the bionanoscience interface.…”

“…For pathogen detection, Taubner et al 2 have developed a nano-enabled biosensor using grating-coupled fluorescent plasmonic-based (GC-FP) detection of SARS-CoV-2 antigens and antibodies. GC-FP can detect a diverse set of SARS-CoV-2 antigens and circulating antibodies from minute (finger prick) quantities of dried patient blood samples.…”