Biomedical Engineering Reference
In-Depth Information
templates than to the corresponding enantiomers. h e assessment of tem-
plate incorporation, template removal, and re-binding was conducted
through UV-vis measurements. Signii cant enhancement of enantiose-
lectivity was achieved by optimization of the i lm thickness and by heat-
treatment of the imprinted i lms. At er subtraction of non-specii c binding,
the optimized i lms provided chiral recognition with the enantioselectivity
of almost 100% for (R)-propranolol and 95% for (S)-propranolol.
Using tribenuron-methyl as a template and
N
,
O
-bismethacryloyl etha-
nolamine as a functional cross linking monomer, a molecularly imprinted
nanowire membrane was prepared over an anodic alumina oxide mem-
brane by Liu
et al
[74]. h e nanowire fabric of the imprinted membrane
was established with a scanning electron microscope and a transmission
electron microscope. However, the nonimprinted particulate membrane is
formed in the absence of a template. Scatchard analysis showed that an equal
class of binding sites were formed in the imprinted nanowire membrane
and the dissociation constant and the maximum numbers of these bind-
ing sites were estimated to be 1.44×10
−5
M and 22.7 μmol/g, respectively.
h e permeation experiments throughout the imprinted membrane and the
nonimprinted one were carried out in a solution containing the template
and its competitive analogs. h ese results demonstrated that the molecu-
larly imprinted nanowire membrane exhibited higher transport selectivity
for the template tribenuron-methyl than its analogs, chlorimuron-ethyl,
thifensulfuron-methyl and
N
-(4-bromophenyl carbamoyl)-5-chloro-1H-
benzo[d] imidazole-2-carboxamide. But the nonimprinted granular mem-
brane had no permselectivity for the four substrates.
A useful molecular imprinted i lm based on chitosan/nai on/nano-
silver/poly quercetin compound was prepared by a compound elec-
trochemical method at parai n-impregnated graphite electrode for
clenbuterol (CLB) sensing, which was characterized by means of i eld
emission scanning electron microscopy (FE-SEM), X-ray photoelectron
spectroscopy spectra (XPS), infrared spectra (IR) and electrochemical
techniques to coni rm the formation [75]. h e molecular imprinted i lm
modii ed electrode was successfully applied to the determination of CLB
with a reliable result. In optimum conditions, CLB at concentrations of
0.3-50.0 μM could be determined with a detection limit of 0.01 μM (3r).
Determination of CLB in practical samples of pork liver showed good
recovery. Lu
et al.
reported a technique of forming nanoi lms of poly-
3-aminophenylboronic acid (pAPBA) on the surfaces of polystyrene (PS)
microbeads for proteins (papain and trypsin) in aqueous [76]. Papain was
chosen as a model to study the feasibility of the technique and trypsin as an
extension. h e results show that pAPBA formed nanoi lms (60-100 nm in
