Satu kajian dibuat pada keadaan elektrokimia bagi menentukan asid askorbik menggunakan biosensor digambarkan didalam kajian ini. Morfologi dan komposisi untuk membran nilon berliang dan sifat-sifat elektrokimia dipasang biosensor berasaskan nylon-6 membran telah diuji menggunakan Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spektroskopi (FTIR), Cyclic Voltammetri (CV) dan Elektrokimia Impedance Spektroskopi (EIS). Keputusan mengesahkan bahawa nylon-6 membran mempunyai bentuk spherulites dengan garis pusat yang seragam dan panjang. Kesan kadar imbasan juga telah dikaji dengan menguji sampel yang mengandungi penyelesaian fosfat penampan (PBS) dan 20mm asid askorbik dalam PBS. A kadar imbasan yang lebih tinggi (50mV/s) didapati menyediakan puncak pengimbasan dalam pengesanan analit. Biosensor juga menunjukkan sambutan yang optimum pada pH 7.0 didalam PBS. Membran nylon-6 juga dipasang pada elektrod karbon atau elektrod karbon berkaca dan elektrokimia diperhatikan dengan menggunakan pelbagai jenis elektrod kerja, termasuk seperti elektron karbon terdedah, yang diubah suai nylon-6 / karbon elektord, terdedah karbon kaca elektrod, diubahsuai nylon-6/karbon berkaca elektrod dan grafit.. Intensiti yang paling tinggi dan puncak telah diperhatikan apabila menggunakan grafit sebagai elektrod kerja. Rintangan pemindahan caj bagi setiap jenis elektrod dianalisis melalui EIS pada pH yang berbeza. Grafit menunjukkan mempunyai nilai yang paling tinggi, bermakna lebih baik untuk digunakan dalam mengesan asid askorbik.
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A simple evaluation on electroanalytical sensing condition for the determination of ascorbic acid using modified biosensor is described. The morphology and composition for the porous nylon membrane and electrochemical properties of assembled membrane-based biosensor were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). The results confirmed that nylon-6 membrane has spherulites with uniform diameters and lengths. As for the sensing application, scan rate effect were studied by testing the samples containing phosphate buffer solution (PBS) and 20mM of ascorbic acid in PBS. A higher scan rate (50mV/s) was found to provide scanning curve in detection of analyte. The biosensor also showed an optimum response at pH 7.0 of PBS. Nylon-6 membrane were also assembled on carbon electrode or glassy carbon electrode hence electrochemical performances were observed by using different types of working electrodes, includes bare carbon electron, modified nylon-6/carbon electrode, bare glassy carbon electrode, modified nylon-6/carbon electrode and graphite. The highest intensity and peak current was observed when using graphite as the working electrode. The charge transfer resistance for each type of electrodes were analysed through EIS at different pH. Graphite showed to have the highest Ret value, means better to be used to detect ascorbic acid.
Evaluation of electroanalytical sensing condition for membrane-based biosensor / Sharmaine Shahibullah