title: Rapid, label-free, electrical whole blood bioassay based on nanobiosensor systems.
abstract: Biomarker detection based on nanowire biosensors has attracted a significant amount of research effort in recent years. However, only very limited research work has been directed toward biomarker detection directly from physiological fluids mainly because of challenges caused by the complexity of media. This limitation significantly reduces the practical impact generated by the aforementioned nanobiosensors. In this study, we demonstrate an In(2)O(3) nanowire-based biosensing system that is capable of performing rapid, label-free, electrical detection of cancer biomarkers directly from human whole blood collected by a finger prick. Passivating the nanowire surface successfully blocked the signal induced by nonspecific binding when performing active measurement in whole blood. Passivated devices showed markedly smaller signals induced by nonspecific binding of proteins and other biomaterials in serum and higher sensitivity to target biomarkers than bare devices. The detection limit of passivated sensors for biomarkers in whole blood was similar to the detection limit for the same analyte in purified buffer solutions at the same ionic strength, suggesting minimal decrease in device performance in the complex media. We then demonstrated detection of multiple cancer biomarkers with high reliability at clinically meaningful concentrations from whole blood collected by a finger prick using this sensing system.
authors: Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, United States.
authors: Hsiao-Kang
authors: HK
authors: Chang
authors: Fumiaki N
authors: FN
authors: Ishikawa
authors: Rui
authors: R
authors: Zhang
authors: Ram
authors: R
authors: Datar
authors: Richard J
authors: RJ
authors: Cote
authors: Mark E
authors: ME
authors: Thompson
authors: Chongwu
authors: C
authors: Zhou
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D001774:Blood Chemical Analysis / Q000295:instrumentation*; D018394:CA-125 Antigen / Q000097:blood; D003217:Conductometry / Q000295:instrumentation*; D003460:Crystallization / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D007335:Insulin-Like Growth Factor II / Q000032:analysis; D008565:Membrane Proteins / Q000097:blood; D050997:Nanomedicine / Q000295:instrumentation; D010051:Ovarian Neoplasms / Q000097:blood* / Q000175:diagnosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling
chemical_list: D014408:Biomarkers, Tumor; D018394:CA-125 Antigen; C451759:MUC16 protein, human; D008565:Membrane Proteins; D007335:Insulin-Like Growth Factor II