Comparison of anti-HER2 antibody immobilization using three different techniques on aluminum-aluminum nitride-aluminum thin films produced by radiofrequency sputtering

Abstract

Aluminum-aluminum nitride-aluminum thin films were deposited by radiofrequency reactive magnetron sputtering on silicon wafers (111). A comparison of three different methods of antibody immobilization relevant for surface modification in biosensor development was undertaken. Antibodies against human epidermal growth factor receptor 2 (HER2), a fundamental protein marker in breast cancer diagnostics, were used as a model in protein identification assays. The techniques evaluated were direct (random) immobilization, alginate (ionic) immobilization, and protein G (oriented) immobilization. Standardized detection capabilities were measured by enzyme-linked immunosorbent assay, and revealed substantial outcomes and differences for each technique. Immobilization using protein G was more efficient. Although immobilization using alginate had lower detection sensibility, it may be compared in sensitivity in some cases and is a more affordable technique.