Sains Malaysiana 46(7)(2017): 1097–1102
http://dx.doi.org/10.17576/jsm-2017-4607-12
Comparative Study of Poly(4-vinylpyridine)
and Polylactic Acid-block-poly(2-vinylpyridine)
Nanocomposites on Structural, Morphological and Electrochemical Properties
(Kajian Perbandingan Nanokomposit Poli(4-vinilpiridine) dan Polilaktik Asid-blok-poli(2-vinilpiridine)
ke
atas Sifat
Struktur, Morfologi dan Elektrokimia)
JIAJIA LONG1, AZLIN SUHAIDA AZMI1, MINSOO P. KIM2 & FATHILAH BINTI ALI1*
1Department of Biotechnology
Engineering, Kulliyyah of Engineering, International
Islamic University Malaysia, P.O. Box 10, 50728 Kuala Lumpur, Federal Territory,
Malaysia
2Ulsan National Institute of
Science and Technology (UNIST), 50 UNIST-gil, Ulsan
44919
South Korea
Diserahkan: 26 Disember 2016/Diterima: 6 Mac 2017
ABSTRACT
Polymer-based nanocomposites
have attracted a lot of attention for amperometric biosensor development due to their general physical and chemical properties
including biocompatibility, film-forming ability, stability and different
functional groups that can be bonded with other biomolecues.
In this study, poly-4-vinlyridine homopolymer (P4VP)
and polylactic acid-block-poly(2-vinylpyridine) block
copolymer (PLA-b-P2VP) were used to hybridize with gold precursors
(Au3+) based on the association
between the nitrogen of the pyridine group of P4VP or P2VP block with gold
precursors. P4VP/Au3+ and PLA-b-P2VP/Au3+ nanocomposites
were prepared with ratio of gold to P2VP or P4VP (10:1). The Au3+ in
both polymers was reduced to gold nanoparticles (AuNPs)
via in-situ approach by using hydrazine. Fourier transform infrared
spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis),
transmission electron microscopy (TEM) and cyclic voltammetry (CV)
were used to characterize the structural, morphological and electrochemical
properties of the nanocomposites. The peak currents of P4VP/AuNPs and PLA-b-P2VP/AuNPs nanocomposites
modified electrode were 6.685 nA and 69.432 nA, respectively, which are much lower
than bare electrode (205.019 nA) due to the
non-conductivity of P4VP and PLA-b-P2VP. In order to improve
the electron transfer capability of electrode, graphene oxide (GO)
was blended and electrochemically reduced to obtain P4VP/AuNPs/rGO and PLA-b-P2VP/AuNPs/rGO nanocomposites. After immobilization of these two
nanocomposites on electrode through drop casting method, the peak currents of
P4VP/AuNPs/rGO and PLA-b-P2VP/AuNPs/rGO nanocomposites modified
electrode were 871.172 nA and 663.947 nA, respectively, which are much higher
than bare electrode (205.019 nA) and shown good
capability to accelerate electron transfer. Based on these characterizations,
P4VP/AuNPs/rGO has
potential as the nanocomposite to modify the electrode for enzymatic biosensor
development.
Keywords: Block copolymers;
cyclic voltammetry; enzyme biosensor; graphene; Poly-4-vinlyridine
ABSTRAK
Nanokomposit polimer bagi pembangunan
biosensor amperometrik menarik
banyak perhatian
kerana sifat fizikal
dan kimia
am mereka termasuk keserasian-bio, keupayaan pembentukan filem, kestabilan dan bergantung kepada kumpulan berfungsi yang berkemampuan untuk terikat dengan biomolekul lain. Dalam kajian ini, poli-4-vinilpiridin
(P4VP) dan polilaktik
asid-blok-poly (2-vinilpiridin)
(PLA-b-P2VP)
telah digunakan
untuk dihibridkan dengan prekursor emas berdasarkan gabungan antara nitrogen kumpulan piridin daripada P4VP atau P2VP blok dengan prekursor
emas (Au3+).
Nanokomposit P4VP/Au3+ dan PLA-b-P2VP/Au3+
telah disediakan dengan nisbah emas
kepada P2VP atau
P4VP (10:1). P4VP/AuNPs
dan PLA-b-P2VP/AuNPs
nanokomposit telah
disediakan melalui pendekatan in-situ dengan menggunakan hidrazin. Spektroskopi
transformasi Fourier inframerah
(FTIR),
spektroskopi ultraviolet boleh
dilihat (UV-vis), mikroskop
elektron penghantaraan
(TEM)
dan voltammetri
berkitar (CV) telah
digunakan untuk
mencirikan sifat struktur, morfologi dan elektrokimia nanokomposit tersebut. Arus puncak untuk
bahan P4VP/AuNPs
dan PLA-b-P2VP/AuNPs
pengubah suai
elektrod adalah 6.685 nA dan
69.432 nA, yang jauh
lebih rendah daripada
nilai elektrod
(205.019 nA) disebabkan sifat tidak kekonduksian
daripada P4VP dan
PLA-b-P2VP.
Dalam usaha
untuk meningkatkan keupayaan pemindahan elektron elektrod, grafin oksida (GO)
telah dicampurkan dan diperoleh dengan
kaedah elektrokimia
bagi penyediaan P4VP/AuNPs/rGO dan
nanokomposit PLA-b-P2VP/AuNPs/rGO. Selepas proses immobilasi oleh bahan nanokomposit pada elektrod melalui
teknik saliran
titisan dengan puncak elektrod arus untuk P4VP/AuNPs/rGO dan
PLA-b-P2VP/AuNPs/rGO nanokomposit
masing-masing diubah
suai menunjukkan nilai 871.172 nA
dan 663.947 nA.
Nilai tersebut jauh lebih tinggi
daripada permukaan
elektrod (205.019 nA)
serta menunjukkan
kemampuan yang baik untuk mempercepatkan pemindahan elektron. Berdasarkan
pencirian ini, P4VP/AuNPs/rGO mempunyai
potensi sebagai
komposit nano untuk
mengubah suai
elektrod bagi pembangunan
enzim biosensor.
Kata kunci: Blok kopolimer; enzim biosensor; grafin;
poli-4-viniliridine; voltammetri berkitar
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*Pengarang untuk surat-menyurat;
email: fathilah@iium.edu.my