Micro-patterning of nanosensor elements using layer-by-layer self-assembly, avidin-biotin chemistry, and photolithography

The miniaturization of biosensors has resulted in the need to develop new techniques to pattern various sensor elements with high resolution and fast response time. This paper describes the selective deposition of various sensor elements on glass as well as on silicon substrate by combining layer-by-layer electrostatic self-assembly, photolithography and avidin-biotin chemistry. Two methods have been developed for this selective patterning. The first method includes selective UV radiation of a coated photobiotin on glass substrate and covalent bonding of avidin-layered fluorescent nanoparticles to the irradiated areas. The second method involves lithography and self-assembly in a modified lift-off process. In both cases, the epifluorescence microscope images show high spatial resolution of patterned areas and excellent surface coverage. These patterns will be further developed for monitoring cell growth in tissue scaffolds.