Towards quantitative point of care detection using SERS lateral flow immunoassays

Sian Sloan-Dennison,Karen Faulds,Duncan Graham,James W Dear,Emma O’Connor

doi:10.1007/s00216-022-03933-8

Sian Sloan-Dennison, Karen Faulds + Show 3 more

Open Access

https://doi.org/10.1007/s00216-022-03933-8

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Abstract

The rapid detection of biomolecules in a point of care (POC) setting is very important for diagnostic purposes. A platform which can provide this, whilst still being low cost and simple to use, is paper-based lateral flow immunoassays (LFIA). LFIA combine immunology and chromatography to detect a target by forming an immunocomplex with a label which traps them in a test zone. Qualitative analysis can be performed using the naked eye whilst quantitative analysis takes place by measuring the optical signal provided by the label at the test zone. There are numerous detection methods available; however, many suffer from low sensitivity and lack of multiplexing capabilities or are poor at providing POC quantitative analysis. An attractive method to overcome this is to use nanoparticles coated in Raman reporters as the labelled species and to analyse test zones using surface-enhanced Raman scattering (SERS). Due to the wide variety of metal nanoparticles, Raman reporter and laser excitations that are available, SERS-based LFIA have been adapted to identify and quantify multiple targets at once. Large Raman microscopes combined with long mapping times have limited the platform to the lab; however, by transferring the analysis to portable Raman instruments, rapid and quantitative measurements can be taken at the POC without any loss in sensitivity. Portable or handheld SERS-LFIA platforms can therefore be used anywhere, from modern clinics to remote and resource-poor settings. This review will present an overview of SERS-based LFIA platforms and the major recent advancements in multiplexing and portable and handheld detection with an outlook on the future of the platform.Graphical abstract

Highlights

Lateral flow immunoassays (LFIA) are paper-based devices used for the rapid detection of analytes and biomolecules in clinical practice
The advantages of LFIA are exploited when the test is used in the community because the platform offers a simple-to-use and cheap-to-produce test that can be readily produced at scale
Point of care (POC) assays based on multiple diverse platforms are being widely developed for a range of biomarkers that inform patient care pathways in hospitals and LFIA may not always be optimally suited

Summary

Introduction

Lateral flow immunoassays (LFIA) are paper-based devices used for the rapid detection of analytes and biomolecules in clinical practice. Quantitative information was obtained based on decreasing intensity of the peaks from the SERS signal of the Raman reporter present in the multiplex test zone spectrum, with decreasing concentrations of the targets [16].

Results

Conclusion