GRAPHENE-HAPTEN-BASED NANOSENSOR FOR ULTRASENSITIVE DETECTION OF BISPHENOL A WITH AN OPTOFLUIDIC BIOSENSING PLATFORM

摘要

Two-dimensional graphene-based materials have emerged as promising transducers in diverse analytical devices owing to its extraordinary optical, electrical, mechanical, and transport properties. Functionalized with biomolecules (e.g. antibody or DNA), graphene-based biosensor have been widely used in immunoassay, medical imaging, clinical/diagnostic assays, and biomolecular binding assay. However, both experiments and simulations have indicated that when biomolecules, whose function relies on a specific tertiary or quaternary structure, are immobilized onto graphene, the significant conformational changes and loss of function have been demonstrated. Combining the advantages of evanescent wave fiber optic sensor and microfluidic technology, a facile and robust all-fiber optofluidics-based immunoassay platform was developed for rapid and ultrasenstive detection of bisphenol A (BPA). BPA, a xenoestrogenic endocrine-disrupting chemical, has been widely detected in environment and food. Through conjugating animated graphene with 4,4-bis-(4-hidroxyphenyl) valeric acid (BVA, a structural analogue of BPA with a carboxyl group), hapten-grafted graphene was employed as the immunological recognition of Cy3-labeled anti-BPA antibody as well as for optical transduction, which could avoid the above-mentioned drawbacks.