Smartphone-based fluorescence sensing is a promising technology for the detection of food allergens. This approach leverages the ubiquity and advanced capabilities of smartphones, combined with novel sensing technologies, to provide a portable, low-cost, and user-friendly platform for allergen detection. The technology involves the use of biosensors and fluorescence signal-enhancing substrates integrated with a smartphone. The smartphone’s camera and embedded flash functions are used to capture images and quantify the fluorescence response, enabling real-time, on-site analysis. This system can identify allergens by their unique fluorescence signatures when exposed to certain wavelengths of light. One of the key advantages of this technology is its potential for widespread use. The simplicity and affordability of the system make it accessible to a broad range of users, from industry professionals to consumers. This could revolutionize food safety, allowing individuals to test their food for allergens wherever and whenever they need. However, while the technology is promising, further research and development are needed to improve its sensitivity and specificity, and to expand the range of allergens it can detect. This chapter summarizes the current trends of smartphone-based fluorescence techniques for foods allergens detection, its limitations and future scopes.