A simple and accurate device for early detection of malignancies is paramount for prompt treatment and prevention of metastases. In this study, we describe a novel fabrication method for producing an ordered nanogold-dot array with strong localized surface plasmon resonance (LSPR) and narrow bandwidth. The array was used as an optical biosensing chip for the detection of vascular endothelial growth factor 165 (VEGF165) in human serum. The biochip was constructed by conjugating an anti-VEGF antibody, a specific biorecognition element for VEGF165, onto the array via the fragment crystallizable (Fc) region of the antibody, ultimately increasing the efficiency of VEGF165 detection. The resulting biochip was sensitive, had a wide linear detection range (0.01-100 ng/mL), was specific for VEGF165 (showing no interference when challenged with glucose and ascorbic acid), and characterized by an excellent stability (allowing storage and transportation at room temperature). Owing to the good correlations of VEGF165 measurements obtained with ELISA, we believe that our chip holds promise as a tool for early diagnosis of cancer.
Keywords: VEGF; early cancer diagnosis; localized surface plasmon resonance; nanogold-dot arrays; optical biosensor.