Navigating the landscape of optical biosensors

• Revolutionizing optical biosensing in focus with AI, ML, IoMT and 5th/6th gen sensing. • Quantum biosensing a pioneering ultrasensitive optical sensing technique reviewed. • Explored trends of optical biosensing in medical, environmental, and food domains. • Navigated the future avenues in optical biosensing. Optical biosensors are analytical devices that leverage the principle of optics to detect and analyze biological molecules or chemical substances. These sensors rely on interactions between light and the target analyte to provide real-time, sensitive, and specific measurements. The newly growing quantum biosensing technology uses the principle of quantum mechanics that has greatly enhanced the sensitivity of biosensors. This led to the evolution in the trends of optical biosensors, which with advancements, continues to develop new technologies such as the Internet of Medical Things (IoMTs) and Artificial intelligence (AI). In this comprehensive review, we have thoroughly discussed the advancements in optical sensors and biosensors used in medical diagnosis, environmental monitoring, and food quality control with an emphasis on quantum biosensing about innovative technologies and developments in optical biosensing. All major optical biosensors' principles with brief working mechanisms are also presented to make readers more intuitive. This review comprehensively delineates the landscape of optical sensing and biosensing, elucidating recent advancements in these domains. The aim of this review is to provide readers with a profound understanding of the scientific intricacies associated with these technologies.