Fabrication of Nanostructures on Optical Fibers Using Nanosphere Lithography for Biosensing

The utilization of top-down nanoparticle fabrication has been investigated to enhance the reusability, longevity, and reproducibility of bottom-up nanoparticle-dependent fiber-optic plasmonic sensors. Au nanostructures were conveniently and economically engineered using nanosphere lithography on conventional optical communication fibers. The refractive index sensing technique was employed to characterize the properties of the produced Au nanotriangles and nanoholes. The efficacy of these patterned nanostructures was demonstrated in the real-time detection of immune responses related to the carbohydrate antigen 19-9, a pancreatic cancer biomarker. Consequently, the triangle-based plasmonic nanoprobe achieved a lower detection limit of 1.06 U/mL. This advancement indicates potential commercialization prospects for reliable and cost-effective devices based on patterned nanostructures as optrodes, thereby establishing their practical utility as biosensors.