Switching from Multiplex to Multimodal Colorimetric Lateral Flow Immunosensor

Abstract

Multiplex lateral flow immunoassay (LFIA) is largely used for point-of-care testing to detect different pathogens or biomarkers in a single device. The increasing demand for multitargeting diagnostics requires multi-informative single tests. In this study, we demonstrated three strategies to upgrade standard multiplex LFIA to multimodal capacity. As a proof-of-concept, we applied the strategies to the differential diagnosis of Human Immunodeficiency Virus (HIV) infection, a widespread pathogen, for which conventional multiplex LFIA testing is well-established. In the new two-parameter LFIA (x2LFIA), we exploited color encoding, in which the binding of multiple targets occurs in one reactive band and the color of the probe reveals which one is present in the sample. By combining the sequential alignment of several reactive zones along the membrane of the LFIA strip and gold nanoparticles and gold nanostars for the differential visualization, in this demonstration, the x2LFIA can furnish information on HIV serotype and stage of infection in a single device. Three immunosensors were designed. The use of bioreagents as the capturing ligand anchored onto the membrane or as the detection ligand labelled with gold nanomaterials affected the performance of the x2LFIA. Higher detectability was achieved by the format involving the HIV-specific antigens as capturing agent and labelled secondary bioligands (anti-human immunoglobulins M and protein G) as the probes.

Ten Years of Lateral Flow Immunoassay Technique Applications: Trends, Challenges and Future Perspectives

“…Recently, the use of a single strip with a single Test line has also been applied for multiplexed detection of target molecules, exploiting surface-enhanced Raman scattering [ 80 , 81 ] and colorimetric detection [ 82 , 83 ]. Moreover, most recently, Cavalera et al proposed a two-parameter multiplexing LFIA strategy (x2LFIA), which combines the spatial resolution with colour encoding approach to expand the number of information achievable within a single strip test, obtaining tetravalent information in a two-line and two-colour assay [ 84 ].…”

Lateral flow assays (LFA) as an alternative medical diagnosis method for detection of virus species: The intertwine of nanotechnology with sensing strategies

“…Immobilized gp36 and gp41 were also used at the TL, and avidin was used at the control line. The color of the test line determined the detected HIV subtype, and the evaluations showed that this approach improved LFA’s performance[ 106 ].…”

Bacterial ligands as flexible and sensitive detectors in rapid tests for antibodies to SARS-CoV-2

“…In a previous work, we demonstrated the high sensitivity and specificity reached by using the total antibody approach [13]. In other studies, the effects of using Staphylococcal protein A (SpA) and Streptococcal protein G (SpG) as detection [14,15] or capturing elements [16] on antibody testing have been explored. Another interesting benefit of bacterial bioligands is their broad selectivity towards immunoglobulins of different animal species.…”

“…However, they bind also to the Fab region (SpA generally very weakly [20], SpG moderately). The use of SpA and SpG as probes in LFA has been reported in several scientific works and for commercially available devices [15,16,21].…”