Application of highly sensitive, modified glass substrate-based immuno-PCR on the early detection of nasopharyngeal carcinoma

In this study, we investigated the utilization of highly sensitive immuno-PCR (IPCR) method as a powerful tool to detect NPC in early disease stage. We established a substrate-ELISA platform as a model system for evaluation of the feasibility of our idea after surface modification process on glass beads. Therein the DNA–antibody conjugation was added to sensitize prior enzyme substrate–antibody complex. In the study, the detection efficiency of two different systems regarding sensitivity, affinity, and specificity was evaluated. Moreover, to show the efficacy of our IPCR system, commercialized ELISA kit was also included for comparison with our IPCR glass substrate-based capture system. The surface physical properties of the modified substrates were also tested with atomic force microscopy and X-ray photoelectron spectroscopy, together with the measurement of the water contact angle. In the results, various factors in the production of IPCR detection system were determined to maximize the effect on assay performance, including the modification of the glass surface properties, primary and secondary antibody optimal concentrations, and biotinylated reporter DNA concentration. We found that the sensitivity of IPCR was approximately over two order magnitude higher than that of conventional ELISA method. The result suggests that our IPCR system could be an applicable and reliable tool for early detection of NPC.