posted on 2007-07-15, 00:00authored byBo He, Sang Jun Son, Sang Bok Lee
A suspension array for multiplexed immunoassays has
been developed using shape-coded silica nanotubes (SNTs)
as coding materials. Fabricated by multistep anodization
template synthesis, each shape-coded SNT has several
segments with different reflectance values depending on
their diameters and wall thicknesses. Therefore, the code
of each SNT can be “read-out” under a conventional
optical microscope. The suspension array with shape-coded SNTs has shown high stability and dispersibility
in aqueous buffer media and high detection sensitivity.
The SNTs have not shown any visible degradation while
submerged in aqueous solution for 7 months, the tubular
structure and silanol groups on the inner and outer
surfaces allow SNTs to disperse evenly in buffer solution,
and the detection limit of an IgG protein is about 6 pM
with 1.5 × 106 SNTs per mL. We have demonstrated the
high selectivity of the SNTs suspension array for the
detection of multianalytes in the multiplexed immunoassay experiments.