To activate the oxidized pSi surface, solution of 0.1 mol L1
NaOH was loaded into the microchannel. After 30 min, the channel
was washed with deionized water to remove the excess amount of
NaOH. Then the microchannel was treated with 0.1 mol L1 HCl
for 30 min, and washed with deionized water. After the channel
was dried with a stream of nitrogen gas, the pSi surface was reacted
with 3% 3-aminopropyltriethoxysilane (APTES, ACROS Organics)
of ethanol solution for 1.5 h. After the channel was washed
with pure ethanol, the amino-terminated surface was then reacted
with 2.5% glutaraldehyde (GA) of aqueous solution for 2.5 h. The
GA activated surface was finally attached with Esherichia coli (E.
coli) antibody by injecting the antibody solution (40 μg L1
) into
the microchannel, which was subsequently store at 4 °C overnight.