Prussian Blue Dispersed Sphere Catalytic Labels for Amplified Electronic Detection of DNA.
A highly sensitive electrochemical DNA hybridization assay using Prussian blue (PB)-modified polymeric spheres as the oligonculeotide labeling tag is described. The sandwich assay relies on a secondary nucleic-acid probe functionalized with polystyrene beads loaded with numerous Prussian blue nanoparticles. The very strong catalytic activity of the captured PB 'artificial peroxidase' tag towards the reduction of hydrogen peroxide, along with the encapsulation of numerous catalytic particles onto polymeric beads, allows amperometric detection of the DNA target down to the 50 fM level (2.5 amol). Imaging and spectroscopic measurements are used to characterize the PB-tagged polystyrene beads. Such coupling of PB catalytic labels with polymeric carrier beads offers great promise for amplified transduction of different biomolecular interactions.
Suwansa-Ard
Siriwan
S
Biodesign Institute, Departments of Chemical Engineering and Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA.
Xiang
Yun
Y
Bash
Ralph
R
Thavarungkul
Panote
P
Kanatharana
Proespichaya
P
Wang
Joseph
J