文摘
Biosensors based on surface plasmon resonance (SPR), operating with the Kretschmann conventional arrangement, have been employed for biomolecular detection of tumor markers. However, the traditional SPR configuration presents some experimental inconveniences that are overcome by using plasmonic substrates based on nanohole arrays manufactured in metallic films. This SPR configuration exhibits the extraordinary optical transmission (EOT) phenomenon, which is explored in the monitoring of binding events that occur on the metal surface. In this work, we proposed a plasmon biosensor based on nanohole arrays built on gold film operating in collinear transmission mode by using spectral investigation for signal transduction. The SPR substrate was coupled to a microfluidic system and showed good sensitivity and linearity. A concentration of 30 ng mL−1 of human epidermal receptor protein-2 (HER2) antigen (associated with breast cancer) was detected using the integrated device; this showed its great potential to be used in tumor diagnosis. Keywords Nanohole arrays Surface plasmon SPR HER2 antigen Tumor marker Breast cancer