Satria Mihardi
@unimed.ac.id
Physics Department
Universitas Negeri Medan
RESEARCH INTERESTS
Education; Physics
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Motlan, Jurubahasa Sinuraya, and Satria Mihardi
AIP Publishing
S. Abd. Hakim, Satria Mihardi, and Abdul Rais
Rasayan Journal of Chemistry
An indicator electrode has been made in two ways using the urease enzyme immobilization technique with Glutaraldehyde (GA) crosslinking at various concentrations (2.6 - 3.0)%. The aim is to choose the best indicator electrode from both methods, this is through XRD, SEM-EDS, and FTIR analysis. The method used is a potentiometric biosensor method. The indicator electrode for the first method is denoted PVA-E-GA/PVC-KTpClPB, meaning that PVA-E is mixed with PVA-E solution coated with PVC-KTpClPB. The indicator electrode of the second method is denoted PVA-E/GA/PVC-KTpClPB, meaning that PVA-E coated with GA is coated with PVC-KTpClPB. Each in 1x, 2x, and 3x layer variations. The best results of GA crosslinking from the first and second methods were at a concentration of 2.9%. The best result of the first method of indicator electrode is PVA-E-GA3x/PVC-KTpClPB1x. the best result of the second method is the indicator electrode PVA-E 1x/GA 1x/PVC-KTpClPB 1x
A Hakim S, S Mihardi, A Rais, Willy, and Y T H Panjaitan
IOP Publishing
Abstract Research has been carried out on the manufacture of tungsten indicator electrodes with a diameter of 1 mm coated with PVA-Enzyme coated with PVC-KTpClPB using the biosensor potentiometer method. It has a sensitivity of 19,096 mV/decade, a detection range of 1.10-5 - 5.10-4 M, a detection limit of 1.10-5 M and a correlation coefficient of R2 = 0.9431. This detection range is very small, only a difference of one order to the negative power. On the basis of this small range, the PVA-Enzyme and PVA-Enzyme-GA solutions have been characterized by UV-vis showing a very clear difference in the width of the absorbance peak at wavelength. The indicator electrodes B1-4 and B3-4 have been analyzed using UV-vis, FTIR, SEM-eds and XRD. The method used is the biosensor poteniometric method, urease enzyme immobilization technique, which analytes urea in determining sensitivity, detection range and detection limit, as well as variable signal analysis of 60 signals/second. The results obtained from the indicator electrode B1-4 have a sensitivity of 46.67 mV/decade, a detection range of 10-4 - 10-2 M and a detection limit of 10-4 M, R2 = 99.62 %. The indicator electrode B3-4 has a sensitivity of 38.16 mV/decade, a detection range of 10-6 - 10-4 M and a detection limit of 10-6 M, R2 = 95.42 %. The best results on electrodes B1-4.
A. Hakim S, M. Situmorang, K. Sebayang, T. Sembiring, K. Tarigan, S. Mihardi, N. M. Noor, and J. Elnovreny
Rasayan Journal of Chemistry
Electrolyte solutions used in potentiometric cells from ion-selective electrode (ISE) sensors urea contribute to a good enzymatic reaction. This study aims to obtain electrolyte solutions that have the best response to ISE on the electrode modification membrane electrode 35 mg PVA-enzyme coating 35 mg PVC-500 mg KTpClPB. Solution analysis begins with the characterization of ISE electrode membranes using UV-vis, SEM-EDX, and XRD, the best results on electrode membranes are used as ISE. Analyzing the solution sequentially is a phosphate buffer solution, KCl phosphate buffer solution and phosphate buffer KCl injection with urea using a potentiometer, power lab, and computer to see the solution response. Based on the results of the computer response obtained a phosphate buffer solution pH 5.5, 0.001 M, 0.001 M KCl, and 0.001 M urea.
S A Hakim, T Sembiring, K Sebayang, M Situmorang, K Tarigan, K Sembiring, S Mihardi, and E N Waruwu
IOP Publishing
Y I Tanjung, A M Siregar, A Bakar, and S Mihardi
IOP Publishing