Among the diverse functions of biomedical products, those for diagnosis own a specialty market because of the increasing demands for early disease detection and chronic disease management. The development of biosensors is considered as a powerful new tool for biomedical diagnosis as it surpasses many conventional methods in regards to time, accuracy and cost, and also facilitates a broad application not only in hospitals and laboratories, but also for patients’ self-monitoring. The global market for biosensors is projected to reach USD 27.1 billion by 2022, with the medical diagnostics segment accounting for a major share of more than 70%. The growing market for biosensors enforces those manufacturers to accelerate the development of new technologies and commercialization of exi...[ Read more ]

Among the diverse functions of biomedical products, those for diagnosis own a specialty market because of the increasing demands for early disease detection and chronic disease management. The development of biosensors is considered as a powerful new tool for biomedical diagnosis as it surpasses many conventional methods in regards to time, accuracy and cost, and also facilitates a broad application not only in hospitals and laboratories, but also for patients’ self-monitoring. The global market for biosensors is projected to reach USD 27.1 billion by 2022, with the medical diagnostics segment accounting for a major share of more than 70%. The growing market for biosensors enforces those manufacturers to accelerate the development of new technologies and commercialization of existing technologies.

In this thesis, three biosensors are developed based on fluorophores with AIE property to target biomarkers that play significant roles in different diseases for relevant diagnostic applications. An abnormal accumulation of lactate, a product of human anaerobic respiration, is one of the most important biomarkers for physical fatigue and a variety of diseases such as hyperlactatemia, renal failure and so on. Therefore, a novel assay employing lactate oxidase (LOx) and an AIE-active fluorophore (TPE-HPro) that detects hydrogen peroxide (H₂O₂) is developed to quantify lactate level with excellent sensitivity and anti-interference performance. Hypoxanthine, a purine derivative, serves as an indicator of intracellular energy status and related pathological conditions such as hypoxia, hyperuricemia and so on. The probe TPE-HPro is thus combined with xanthine oxidase (XO) to achieve a sensitive and repeatable detection of hypoxanthine. Galectin-3 is a protein that has important roles in cancer progression, including angiogenesis, metastasis and so on. A novel AIE-based nanoparticle probe (TPE-(LN)₂) is designed and synthesized to target galectin-3 based on the carbohydrate-protein interaction. The TPE-(LN)₂ probe binds to galectin-3 to form large complexes along with significant fluorescence change, which realizes a rapid, sensitive and specific detection of galectin-3.

However, there exists a gap between the biosensors developed in the laboratory and the commercial products. A systematic procedure for design of commercial enzymatic biosensors for body fluid analysis is thus developed by integration of knowledge and experience in biosensors and conceptual product design framework. This work speeds up the design process by guiding designers to make key decisions step by step with the aid of rule-based methods, model-based methods, experiments and databases. The design procedure is illustrated with the design and development of a lactate biosensor which shows excellent performance in the test of real saliva samples.