Carbon nanotube amplification strategies for highly sensitive immunodetection of cancer biomarkers

Autor: Fotios Papadimitrakopoulos, Xin Yu, James F. Rusling, Sang N. Kim, Joseph D. Gong, J. Silvio Gutkind, Vyomesh Patel, Bernard Munge, Gary C. Jensen, John W. Gillespie, Ashwin Bhirde
Rok vydání: 2006
Předmět:
Zdroj: Journal of the American Chemical Society. 128(34)
ISSN: 0002-7863
Popis: We describe herein the combination of electrochemical immunosensors using single-wall carbon nanotube (SWNT) forest platforms with multi-label secondary antibody-nanotube bioconjugates for highly sensitive detection of a cancer biomarker in serum and tissue lysates. Greatly amplified sensitivity was attained by using bioconjugates featuring horseradish peroxidase (HRP) labels and secondary antibodies (Ab(2)) linked to carbon nanotubes (CNT) at high HRP/Ab(2) ratio. This approach provided a detection limit of 4 pg mL(-)(1) (100 amol mL(-)(1)), for prostate specific antigen (PSA) in 10 microL of undiluted calf serum, a mass detection limit of 40 fg. Accurate detection of PSA in human serum samples was demonstrated by comparison to standard ELISA assays. PSA was quantitatively measured in prostate tissue samples for which PSA could not be differentiated by the gold standard immunohistochemical staining method. These easily fabricated SWNT immunosensors show excellent promise for clinical screening of cancer biomarkers and point-of-care diagnostics.
Databáze: OpenAIRE