Microlasers made entirely from edible substances

Biolasers composed of biological and biocompatible materials are increasingly used in biomedical applications, including cell barcoding and biosensing. However, no studies have focused on creating lasers from edible substances. Here, consumable substances for both the laser cavity and the gain material are systematically explored. Several fluorescent dyes are identified as effective gain materials for lasing. Two types of microcavities are demonstrated: whispering gallery mode and Fabry–Pérot. The edible microlasers are employed as sensors and barcodes. Due to their extremely narrow spectral lines, the microlasers provide exceptional sensitivity to various environmental factors. They are designed to sense sugar concentration, pH, the growth of bacteria, and exposure to too-high temperatures. Additionally, they encode multiple data bits, such as manufacturer information and expiration dates, while also functioning as physical unclonable functions for anti-counterfeiting. The microlasers developed in this study are entirely safe for consumption, do not alter the appearance or taste of food, and are environmentally friendly. Unlike traditional barcodes and sensors placed on the packaging, edible lasers can be embedded directly into edible products. They can significantly enhance traceability, security, and freshness monitoring of food and pharmaceuticals as well as non-edible products and can be employed for environmental monitoring and biomedical applications.