Recent Advancements in Enzyme-Based Lateral Flow Immunoassays

Abstract

Paper-based lateral-flow immunoassays (LFIAs) have achieved considerable commercial success and their impact in diagnostics is continuously growing. LFIA results are often obtained by visualizing by the naked eye color changes in given areas, providing a qualitative information about the presence/absence of the target analyte in the sample. However, this platform has the potential to provide ultrasensitive quantitative analysis for several applications. Indeed, LFIA is based on well-established immunological techniques, which have known in the last year great advances due to the combination of highly sensitive tracers, innovative signal amplification strategies and last-generation instrumental detectors. All these available progresses can be applied also to the LFIA platform by adapting them to a portable and miniaturized format. This possibility opens countless strategies for definitively turning the LFIA technique into an ultrasensitive quantitative method. Among the different proposals for achieving this goal, the use of enzyme-based immunoassay is very well known and widespread for routine analysis and it can represent a valid approach for improving LFIA performances. Several examples have been recently reported in literature exploiting enzymes properties and features for obtaining significative advances in this field. In this review, we aim to provide a critical overview of the recent progresses in highly sensitive LFIA detection technologies, involving the exploitation of enzyme-based amplification strategies. The features and applications of the technologies, along with future developments and challenges, are also discussed.

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

“…Although LFIAs are inherently the ideal qualitative screening method, they have been asked to be a quantitative method that allows the analyte ultrasensitive detection. A lot of efforts have been made in this direction thanks to the use of new labels and/or strategies to improve the sensitivity, and to the use of dedicated strip readers [ 15 , 16 , 17 , 34 , 267 ].…”

“…While on the one hand the use of readers increases the cost per analysis, on the other it allows data digitalization, tracking, storage, and transmission reducing interpretation and transcription errors, thus ensuring testing quality and control [ 18 ]. In this sense, we are also witnessing an increasing exploitation of the built-in smartphone technology to be used as LFIA reader, as increasingly reported in the literature [ 122 , 132 , 267 , 268 , 269 , 270 , 271 , 272 , 273 , 274 , 275 ]. Moreover, the use of strip readers paved the way for the use of alternative detection methods (fluorescence, chemiluminescence, etc.)…”

Integrated Nanomaterials and Nanotechnologies in Lateral Flow Tests for Personalized Medicine Applications

“…The use of enzymes has been proposed as a chemical enhancement for signal amplification in LFTs [ 47 ]. Usually, catalytic amplification is obtained by exploiting natural enzymes such as horseradish peroxidase (HRP) to catalyze oxidation–reduction reactions at the level of the test and control lines [ 48 , 49 , 50 ].…”

“…In terms of maintaining of the well-known LFT benefits, it is to be considered that in general when using nanozymes (as in the case of natural enzymes) an additional operation step, i.e., the delivery of the chromogenic substrate, is required in comparison to traditional LFTs. However, ad hoc solutions can be developed, including for instance the pre-deposition of the substrate in the nitrocellulose membrane or its dispensing through preloaded cartridges [ 47 ]. In addition, besides the colorimetric technique, other detection methods can be used (e.g., chemiluminescence) depending on the selected nanozyme/substrate system.…”

Antibodies as Biosensors’ Key Components: State-of-the-Art in Russia 2020–2021

“…Immunochromatographic test systems are widespread worldwide owing to the simplicity of their use and visualization of the results [82,83]; their mass production has been established. More often, immunochromatography is used to determine the content of specific antibodies in studied biological fluids.…”