Elektroda selektif ion (ISE) Kalium merupakan salah satu sensor kimia yangbanyak dikembangkan karena penting dan praktis dalam aplikasi biomedis. Prinsip kerjaISE yaitu dengan mengukur aktivitas ionik menggunakan metode potensiometri. ISEyang digunakan dalam penelitian ini adalah Screen Printed Electrode (SPE) , denganmenggunakan voltametri siklik (CV), lapisan polianilin diendapkan pada elektrodakarbon, dengan pemindaian mikroskop elektron. Polianilin (PANI) digunakan sebagaitransduser karena memiliki konduktivitas yang tinggi di dalam air dan mudah disintesis.Polimetil metakrilat – Butil Akrilat digunakan sebagai ion selektif membran (ISM) danvalinomisin digunakan sebagai ionofor selektif. Modifikasi dilakukan dengan metodepotensiometri melalui voltametri siklik. Hasil modifikasi ISE dikarakterisasimenggunakan Fourier-TransformInfraRed Spectroscopy (FTIR) dan Scanning ElectronMicroscopy (SEM). Uji performma analisis terhadap ion kalium dilakukan denganpengukuran linearitas, Limit of Detection (LOD), selektivitas, presisi dan akurasi.Persamaan yang didapat dari uji linearitas ,dengan y = - 61,119x + 407,46 dengan nilaiR2 sebesar 0,9924, yang menunjukkan bahwa nilai sensitivitas yang didapat dari ISEtermodifikasi yaitu sebesar 58,175 mV, dan limit of detection (LOD) pada penelitian inisebesar 10-5,4866 dimana ion Kalium dapat terdeteksi.ISE memmiliki selektifitas yang baikdengan nilai koefisien selektifitas masing- masing terhadap ion Na sebesar 3,659 x 10-4,Mg sebesar 1,719 x 10-10, dan Ca sebesar 2,351 x 10-9

---

Potassium ion selective electrode (ISE) is one of the chemical sensors that has been

widely developed because it is important and practical in biomedical applications. The

working principle of ISE is to measure ionic activity using the potentiometric method.

The ISE used in this study is a Screen Printed Electrode (SPE), using cyclic voltammetry

(CV), a polyaniline layer is deposited on a carbon electrode, by scanning electron

microscopy. Polyaniline (PANI) is used as a transducer because it has high conductivity

in water and is easy to synthesize. Polymethyl methacrylate – Butyl Acrylate was used as

an ion selective membrane (ISM) and valinomycin was used as a selective ionophore.

Modification is done by potentiometric method through cyclic voltammetry. The

modified ISE was characterized using Fourier-Transform InfraRed Spectroscopy (FTIR)

and Scanning Electron Microscopy (SEM). The analysis performance test of potassium

ion was carried out by measuring linearity, Limit of Detection (LOD), selectivity,

precision and accuracy. The equation obtained from the linearity test, with y = -61.119x

+ 407.46 with an R2 value of 0.9924, which indicates that the sensitivity value obtained

from the modified ISE is 58.175 mV, and the limit of detection (LOD) in this study of

10-5.4866 where Potassium ions can be detected. ISE has a good selectivity with a

selectivity coefficient of 3.659 x 10-4 for Na ions, 1.719 x 10-10 for Mg, and 2.351 x 10-

9 for Ca.