title: Comparison of surface plasmon resonance and capacitive immunosensors for cancer antigen 125 detection in human serum samples.
abstract: This paper presents a comparison between surface plasmon resonance (SPR) and capacitive immunosensors for a flow injection label-free detection of cancer antigen 125 (CA 125) in human serum. Anti-CA 125 was immobilized on gold surface through a self-assembled monolayer. Parameters affecting the responses of each system were optimized. Under optimal conditions, SPR provided a detection limit of 0.1 U ml(-1) while 0.05 U ml(-1) was obtained for the capacitive system. Linearity for SPR was between 0.1 and 40 U ml(-1) and 0.05-40 U ml(-1) for capacitive system. These immunosensors were applied to analyze CA 125 concentrations in human serum samples and compared with conventional enzyme linked fluorescent assay (ELFA). Both systems showed good agreement with ELFA (P<0.05). Moreover, these immunosensors were very stable and provided good reproducible responses after regeneration, up to 32 times for SPR and 48 times for capacitive system with relative standard deviation lower than 4%. The SPR immunosensor provided advantages in term of fast response and real-time monitoring while capacitive immunosensor offered a sensitive and cost-effective method for CA 125 detection.
authors: Trace Analysis and Biosensor Research Center, Department of Chemistry, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
authors: Siriwan
authors: S
authors: Suwansa-ard
authors: Proespichaya
authors: P
authors: Kanatharana
authors: Punnee
authors: P
authors: Asawatreratanakul
authors: Booncharoen
authors: B
authors: Wongkittisuksa
authors: Chusak
authors: C
authors: Limsakul
authors: Panote
authors: P
authors: Thavarungkul
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D015374:Biosensing Techniques / Q000295:instrumentation*; D001774:Blood Chemical Analysis / Q000295:instrumentation*; D018394:CA-125 Antigen / Q000097:blood*; D025802:Electric Capacitance; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D009363:Neoplasm Proteins / Q000032:analysis; D010051:Ovarian Neoplasms / Q000097:blood* / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D014408:Biomarkers, Tumor; D018394:CA-125 Antigen; D009363:Neoplasm Proteins