Advancements in visualizing loop-mediated isothermal amplification (LAMP) reactions: A comprehensive review of colorimetric and fluorometric detection strategies for precise diagnosis of infectious diseases

In the context of global disease conditions and the associated mortality attributed to pathogens, nucleic acid amplification tests are crucial for precise and prompt diagnosis of infectious diseases. Among these tests, loop-mediated isothermal amplification (LAMP) has gained prominence due to its rapidity, simplicity, and high sensitivity. Visualizing the results of LAMP reactions is crucial for their application in diverse fields, and this comprehensive review explores recent advancements in colorimetric and fluorometric detection strategies. Beginning with an overview of global disease burdens and the significance of nucleic acid amplification tests, we delve into the LAMP reaction mechanism, focusing on deoxyribonucleic acid (DNA) polymerization and the associated by-products. Visualization of LAMP reactions can be categorized into indirect and direct detection methods. For indirect detection, we explore various techniques, including turbidity measurements and the use of colorimetric and fluorometric molecules for pH, Mg2+, and pyrophosphate (PPi) measurement. Techniques enabling direct detection of LAMP reactions are covered comprehensively, encompassing DNA-targeting colorimetric and fluorescent dyes, DNA hydrolysis, DNAzyme-based detection probes, Taqman probes, nanoparticles-based DNA hybridization probes, and the emerging role of nanozymes. Each of these methods offers unique advantages and applications in the visualization of LAMP reactions. This review provides a comprehensive overview of recent advances in detection strategies for LAMP reactions, shedding light on their potential in improving the diagnosis of infectious diseases and highlighting their versatility in various fields such as clinical diagnostics, environment monitoring, and food safety.