Detection of soluble ERBB2 in breast cancer cell lysates using a combined label-free/fluorescence platform based on Bloch surface waves

We report on the use of one-dimensional photonic crystals to detect clinically relevant concentrations of ERBB2/neu/Her2 in cell lysates. ERBB2 is a pivotal breast cancer biomarker and targetable oncogenic driver associated with aggressive breast cancer subtypes. To quantitate soluble ERBB2, we developed an optical platform that combines label-free and fluorescence detection modes. Such platform makes use of a sandwich assay in which the one-dimensional photonic crystals sustaining Bloch surface waves are tailored with a monoclonal antibody for highly specific biological recognition (BSW biochip). In a second step, a second antibody to ERBB2 quantitatively detects the bound analyte. The strategy of the present approach takes advantage of the combination of label-free and fluorescence techniques, making bio-recognition more robust and sensitive. In the fluorescence operation mode, the platform can attain the limit of detection 0.3ng/mL (1.5pM) for ERBB2 in cell lysates. Such resolution meets the international guidelines and recommendations (15ng/mL) for diagnostic ERBB2 assays that in the future may help to more precisely assign therapies counteracting cancer cell proliferation and metastatic spread. •Novel platform based on 1D photonic crystal biochips combining label-free and fluorescence detection.•Breast cancer biomarker ERBB2 detection by means of purposely developed specific antibodies.•Detection of 3.5ng/mL ERBB2 in cell lysates demonstrated, with an estimated limit of detection (LoD) of 0.3ng/mL (1.5 pM).•The LoD meets the clinically relevant threshold for ERBB2 detection (15ng/mL), with a duration of the assay of only 30min.•Improved label-free resolution compared to other combined label-free/fluorescence platforms.