Label-free biosensing by means of periodic lattices of high aspect ratio SU-8 nano-pillars.

We developed biophotonic sensing arrays of 60x60 microm(2) made of periodic lattices of high aspect ratio SU-8 nano-pillars in order to demonstrate their capability for label-free molecule detection, as well as the sensitivity enhancement in comparison with a single layer of SU-8. The biophotonic sensing arrays, that we call BICELLs (Biophotonic sensing cells), are interrogated vertically by using micron spot size Fourier transform visible and IR spectrometry (FT-VIS-IR). We monitored the surface immobilization of bovine serum albumin (BSA) antigen and anti-BSA antibody (aBSA) recognition. The bioassay exhibits a limit of detection (LOD) in the order of 2 ng/ml limited by the wavenumber uncertainty during the interrogation process. We also estimated and compared the theoretical biolayer thickness with previous results. Copyright 2010 Elsevier B.V. All rights reserved.