Nano-bio-chips for high performance multiplexed protein detection: determinations of cancer biomarkers in serum and saliva using quantum dot bioconjugate labels.
The integration of semiconductor nanoparticle quantum dots (QDs) into a modular, microfluidic biosensor for the multiplexed quantitation of three important cancer markers, carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), and Her-2/Neu (C-erbB-2) was achieved. The functionality of the integrated sample processing, analyte capture and detection modalities was demonstrated using both serum and whole saliva specimens. Here, nano-bio-chips that employed a fluorescence transduction signal with QD-labeled detecting antibody were used in combination with antigen capture by a microporous agarose bead array supported within a microfluidics ensemble so as to complete the sandwich-type immunoassay. The utilization of QD probes in this miniaturized biosensor format resulted in signal amplification 30 times relative to that of standard molecular fluorophores as well as affording a reduction in observed limits of detection by nearly 2 orders of magnitude (0.02 ng/mL CEA; 0.11 pM CEA) relative to enzyme-linked immunosorbent assay (ELISA). Assay validation studies indicate that measurements by the nano-bio-chip system correlate to standard methods at R(2)=0.94 and R(2)=0.95 for saliva and serum, respectively. This integrated nano-bio-chip assay system, in tandem with next-generation fluorophores, promises to be a sensitive, multiplexed tool for important diagnostic and prognostic applications.
Jokerst
Jesse V
JV
Department of Chemistry and Biochemistry, University of Texas at Austin, 1 University Station A5300, Austin, TX 78712, USA.
Raamanathan
Archana
A
Christodoulides
Nicolaos
N
Floriano
Pierre N
PN
Pollard
Amanda A
AA
Simmons
Glennon W
GW
Wong
Jorge
J
Gage
Carole
C
Furmaga
Wieslaw B
WB
Redding
Spencer W
SW
McDevitt
John T
JT
D014408:Biomarkers, Tumor / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation; D001774:Blood Chemical Analysis / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D036103:Nanotechnology / Q000295:instrumentation*; D009363:Neoplasm Proteins / Q000032:analysis*; D009369:Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D040081:Protein Array Analysis / Q000295:instrumentation*; D045663:Quantum Dots; D012463:Saliva / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation; D013194:Staining and Labeling / Q000379:methods
D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins