Review of Recent Advances in Aptasensor for the Detection of Pathogenic Escherichia coli O157: H7

Escherichia coli (E. coli) O157: H7 is a critical pathogen due to its association with severe conditions like hemorrhagic colitis and hemolytic uremic syndrome. The prevalence of this pathogen underscores the urgent need for effective food and environmental safety measures. Among emerging innovations, aptamer-based biosensors (aptasensors) offer increased sensitivity and reduced detection times compared to traditional methods for identifying E. coli O157: H7. Aptamers, short single-stranded DNA (ssDNA) or RNA molecules, act as bio-recognition elements, exhibiting high specificity and affinity for foodborne pathogens. This scoping review examines recent advancements in aptasensor technology over the past 5 years, focusing on platforms targeting E. coli O157: H7 detection. Key elements such as detection targets, sample types, transducers, sensing mechanisms, fabrication methods, and detection limits were analyzed to identify the strengths and limitations of current aptasensor platforms. The findings indicate that most optical aptasensors, particularly fluorescence-based ones, have been developed for detecting E. coli O157: H7 in water, food, and milk samples. Currently developing aptasensors show promise, offering reliable alternatives with improved detection capabilities. Nonetheless, further studies are still needed to validate their sensitivity and specificity to facilitate broader applications. This review explores the latest developments across diverse aptasensor types, including electrochemical, optical, and magnetic approaches, and examines their working principles, advantages, and limitations. It highlights the potential of aptasensors for practical applications in agricultural and environmental samples, emphasizing their role in advancing safety monitoring systems.