Biomedical Engineering Reference
In-Depth Information
as the immobilization matrix for electrochemical biosensors [121, 122] and
bio-electrocatalysis [123, 124]. In addition, the surface chemistry of AuNRs
is versatile and mobile, allowing the linking of various bio functional groups,
like sugars, nucleic acids, amphiphilic polymers and proteins, through strong
Au-S or Au-N bonding or through physical adsorption and other properties
[125, 126]. h erefore, AuNRs can improve by adhering ability of the com-
posite i lm on surface of electrode and provide an ideal matrix for enzyme
immobilization and biosensor fabrication [123, 127].
Polyaniline (PANI), a conducting polymer with chemical stabil-
ity, biocompatibility and good electrochemical activity, has been widely,
repository used in the DNA biosensor [128, 129]. Compared with a gold
nanoparticle or carbon nanotube-based DNA biosensor, the conducting
PANI-based DNA biosensor has some advantages: tunable conductivity,
low-temperature synthesis, and there is no need for purii cation, end open-
ing, or catalytic deposition processing. Unfortunately, PANI is usually less
favourable condition as the element in biosensor construction because it
has relative low conductivity than the carbon nanotube as well as their non
oriented nanoi bre morphology which leads to low detection sensitivity.
However, when a PANI nanotube array of well-organized orientation is
fabricated and interchanged on electrodes using the well-designed synthe-
sis approach, achievement of enhanced detection sensitivity, which is very
similar to the gold nanoparticle- and carbon nanotube-based detecting
system for DNA hybridization.
7.7
Platinum Material Used in Medicine
h e signii cant similarity between the co-ordination chemistry of Pd(II) and
Pt(II) compounds has advocated specii c studies of Pd(II) complexes as an
antitumor drugs, whereas the higher liability and ai nity in ligand exchange
at Pd centre (10
5
-fold vs Pt) causes for rapid hydrolysis processes which leads
to the dissociation of complex of Pd(II) and the reactive species that is unable
to reach their pharmacological targets has been formed [130]. h ese prob-
lems could be overcome and resolved by using the chelating ligands and bulky
heterocyclic. A very promising and enhancing antitumor characteristics
have been shown by a number of palladium complexes with aromatic N-and
N,N-containing ligands[131, 132]. Recent studies when experimented dem-
onstrated that some Pd(II) complexes exhibit a noticeable
in vitro
cytotoxic
activity, comparable to standard platinum- based drugs, carboplatin, cispla-
tin and oxaliplatin [133]. Metal complexes has received a lot of attentions
and attraction that contain Salen type ligands due to their versatility and
