Label-free and sensitive sialic acid biosensor based on organic electrochemical transistors

This work presented a simple, label-free, and selective device for noninvasive cancer cell identification by sensitive sialic acid (SA) detection using the organic electrochemical transistors (OECTs), which is based on screen-printed carbon source and drain electrodes on flexible substrates and poly (3-aminophenylboronic acid) (PABA)-modified glass carbon (GC) gate electrodes. The transfer and output characteristics of the prepared OECTs were investigated. The success of PABA modification was also verified and characterized. The SA detection principle by the OECTs is directly based on the selective interaction between the SA and phenylboronic acid group on the PABA/GC gate without any enzymatic and labeling procedures. Under optimized conditions, the OECT device exhibits good analytical performances for free SA detection. The limit of detection was 8 mu M, and the response was linear to 2.0 mM (R-2 = 0.9927). More importantly, the OECT device has the capacity to identify cancer and normal cells (here human cervical cancer, HeLa and endothelial cells cultured from human umbilical vein, HUVEC were used as models) in a simple and noninvasive way, showing great potential for providing adjunct to tumor malignancy during intra- or postoperative diagnoses. (C) 2016 Elsevier B.V. All rights reserved.