Electrochemical characterization of polylactic acid-block-poly (2-vinylpyridine)/gold nanoparticle composites for glucose biosensor development

• Main Authors: Ali, Fathilah, Long, JiaJia, Wan Salim, Wan Wardatul Amani
• Format: Article
• Language: English; English
• Published: Kulliyah of Engineering, International Islamic University Malaysia (IIUM) 2017
• Subjects: TP1080 Polymers, plastics and their manufacture
• Online Access: http://irep.iium.edu.my/59806/7/59806-Electrochemical%20characterization%20of%20polylactic%20acid-block-poly.pdf; http://irep.iium.edu.my/59806/13/Electrochemical%20characterization%20of%20polylactic%20acid-block-poly%20%282-vinylpyridine%29%20gold%20nanoparticle%20composites%20for%20glucose%20biosensor%20development.pdf; http://irep.iium.edu.my/59806/; http://journals.iium.edu.my/ejournal/index.php/iiumej/article/view/727/468
• Institution: Universiti Islam Antarabangsa Malaysia

Nanocomposites that consist of diblock copolymer (BCP) and gold nanoparticles (AuNPs) can be applied as a matrix to immobilize enzymes or other molecules, based on the well-defined core/shell nanostructures of these composites. In this research, polylactic acid-block-poly(2-vinylpyridine) (PLA-b-P2VP)/hydrogen tetrachloroaurate(III) hydrate (HAuCl4.3H2O) composites were hybridized and then reduced in dichloromethane (DCM) solution. The hybridizations between gold precursors and the P2VP domain were prepared with different ratios of gold to P2VP block (1:1, 1:5, 1:10, 5:1, 10:1) by taking advantage of the association between the longpair nitrogen of the pyridine group of P2VP. The reduction of the Au3+/PLA-b-P2VP composite was accomplished by hydrazine solution in order to get gold nanoparticle/PLA-b-P2VP composites, which was visually confirmed by a direct color change from bright yellow to purple. In this work, ultraviolet–visible (UV-vis) spectroscopy and Fourier transform infrared spectroscopy (FTIR) were used to confirm the association between gold precursors and pyridine groups as well as the synthesis of gold nanoparticles. The composite which labeled as R3 (Au3+: P2VP = 10:1) showed the highest peak current based on the cyclic voltammetry (CV) measurement. Furthermore, graphene oxide (GO) was added into R3 to prepare BCP/AuNPs/GO composite and reduced to BCP/AuNPs/rGO through electrochemical reduction. The resulting BCP/AuNPs/rGO showed high potential to be used in amperometric biosensor Nanokomposit yang terdiri daripada diblok kopolimer (BCP) dan nanopartikel emas (AuNPs) boleh digunakan sebagai matrik untuk memegun enzim atau molekul lain berdasarkan struktur asas nano komposit. Dalam kajian ini, polilaktik asidblok-poli(2-vinylpyridine) (PLA-b-P2VP)/hidrogen tetrachloroaurate (III) hidrat (HAuCl4.3H2O) komposit telah dihibrid dan kemudian direduksi dalam larutan diklorometana (DCM). Proses hibridasi antara prekursor emas dan domain P2VP dilakukan dengan nisbah yang berbeza; emas kepada blok P2VP (1:1, 1:5, 1:10, 5:1, 10:1) dengan mengambil peluang daripada gabungan antara kumpulan nitrogen dan kumpulan P2VP piridina. Reduksi komposit Au 3+/ PLA-b-P2VP dapat dihasilkan dengan larutan hidrazin bagi mendapatkan komposit nanopartikel emas/PLA-b-P2VP, ini disahkan dengan perubahan warna daripada kuning kepada ungu. Dalam kajian ini, kehadiran-ultraungu spektroskopi (UV-vis) dan perubahan Fourier inframerah (FTIR) telah digunakan untuk mengesahkan hubungan antara prekursor emas dan kumpulan piridina serta sintesis emas nanopartikel. Komposit yang dilabelkan sebagai R3 (Au3+ : P2VP = 10:1) menunjukkan puncak tertinggi arus berdasarkan nilai kitaran voltammetri (CV). Tambahan, graphene oksida (GO) telah ditambah ke dalam R3 untuk menyediakan komposit BCP/AuNPs/GO dan menukarkan kepada BCP/AuNPs/rGO melalui teknik penurunan elektrokimia. Keputusan komposit BCP/AuNPs/rGO menunjukkan potensi yang tinggi untuk digunakan dalam biosensor amperometrik.