Ricciardi, S.S.RicciardiFrascella, F.F.FrascellaAngelini, A.A.AngeliniLamberti, A.A.LambertiMunzert, P.P.MunzertBoarino, L.L.BoarinoRizzo, R.R.RizzoTommasi, A.A.TommasiDescrovi, E.E.Descrovi2022-03-052022-03-052015https://publica.fraunhofer.de/handle/publica/24019110.1016/j.snb.2015.03.0632-s2.0-84927595764An optofluidic chip based on a multilayered photonic crystal structure is employed for an efficient beaming of the emitted radiation in a fluorescent microarray assay. Upon a near-field coupling of fluorescent emitters to surface modes sustained by the photonic crystal, a significant portion of radiated energy is diffracted out-of-plane towards the collection optics. The improvement in fluorescence collection is experimentally demonstrated in an antibody-antigene immunoassay. As a result, a decrease of the limit of detection for labelled antigenes by a factor of about 40 is demonstrated to occur in a robust and reproducible way, with little or no optical alignment issues.en541journal article