Gold Nanoparticles-Based Colorimetric Assays Using Aptamers for Rapid Detection of Food- and Water-Borne Infections in Low-Income Countries

Abstract

Food and water are essential resources for human survival; however, the increasing global population, urbanization, and climate change have placed a significant strain on their availability and safety, with major implications for public health and economic stability. Microbial contamination of food and water remains a critical global challenge, with bacteria responsible for more than 90% of foodborne illnesses. In the past decade, pathogens such as Salmonella, Campylobacter, and Listeria have been the leading causes of outbreaks. In contrast, diseases such as listeriosis and cholera constantly affect several African countries, with rapidly escalating infection rates. Early detection of pathogens in food and water is essential to prevent the spread of infections and reduce associated morbidity and mortality. Although current laboratory-based and on-site detection methods are highly sensitive and reliable, they are often limited by long assay times, labor-intensive procedures, and the need for specialized equipment and trained personnel. These limitations highlight the urgent need for rapid, cost-effective, and user-friendly diagnostic tools suitable for point-of-care (PoC) applications, particularly in resource-limited settings. While recent studies have explored nanomaterial-based detection strategies, existing reviews largely provide descriptive summaries and often lack a critical comparison of emerging biorecognition elements and their practical applicability in low-resource environments. This review provides a comprehensive and critical evaluation of aptamer-integrated gold nanoparticles (AuNPs)-based colorimetric assays, with a particular focus on lateral flow assays (LFAs) for the rapid detection of food- and water-borne pathogens. Key aspects, including assay performance, advantages and limitations of aptamer-based systems, and their potential for deployment in low-income countries (LICs) are discussed. By highlighting current advances, existing challenges, and future perspectives, this review aims to support the development of accessible and scalable diagnostic platforms for improving food and water safety.