Direct Competitive Assay for ERBB2 Detection in Breast Cancer Cell Lysates Using 1-D Photonic Crystals-Based Biochips

ERBB2 is a member of the tyrosine kinase receptor family, a major cancer driver, and a recognized therapeutic target in many cancers, most importantly breast cancer. Its presence in soluble form in blood correlates with tumor expression and may have implications for diagnostic and therapeutic decisions. Herein, we develop a new approach that makes use of a direct competitive ERBB2 assay and 1-D photonic crystal-based biochips. Such biochips permit to operate in a combined label-free/fluorescence mode enabling ERBB2 biosensing in lysates from selected breast cancer cells, either ERBB2-positive (SK-BR 3, BT474) or ERBB2-negative (T47D). Moreover, our biochips allow the collection of enhanced fluorescence spectra, providing a highly specific ERBB2 detection in the three model cell lines. The main advantage of the assay developed in this work lies in the single-step detection procedure that reduces assay turnaround time to less than 20 min. This latter feature confirms the great potential of the technique in the rapid detection of ERBB2 in complex biological media.