Deteksi Simultan Kuersetin dan Rutin Menggunakan Screen-Printed Carbon Electrode Termodifikasi Grafena - Tamida Elinda; Wulan Tri Wahyuni; Eti Rohaeti (Syarif Hidayatullah State Islamic University, 2019)
Kuersetin dan rutin merupakan senyawa antioksidan alami yang termasuk golongan flavonoid. Senyawa ini dapat dideteksi dengan beberapa teknik analisis, salah satunya dengan teknik elektrokimia. Pada penelitian ini, deteksi simultan kuersetin dan rutin dilakukan dengan teknik voltametri siklik menggunakan screen printed carbon electrode (SPCE) termodifikasi grafena. Elektrode disiapkan melalui modifikasi elektrode kerja SPCE dengan campuran grafena:natrium poliakrilat (1:1). Larutan etanol 70%:bufer fosfat pH 7 (6:4) digunakan sebagai elektrolit dalam pengukuran kuersetin dan rutin. Hasil penelitian menunjukkan puncak oksidasi kuersetin dan rutin terdeteksi pada potensial 0.179 V dan 0.310 V vs Ag/AgCl. SPCE termodifikasi grafena menghasilkan intensitas arus oksidasi dan sensitivitas yang lebih tinggi pada pengukuran kuersetin dan rutin. Deteksi simultan kuersetin dan rutin menggunakan SPCE termodifikasi grafena menunjukkan linearitas dengan R2 = 0.9905 dan R2 = 0.9816, masing-masing untuk kuersetin dan rutin. Limit deteksi pengukuran kuersetin dan rutin masing-masing sebesar 0.5369 mM dan 0.7495 mM serta limit kuantitasi sebesar 1.7898 mM dan 2.4985 mM. Presisi pengukuran kuersetin dan rutin memiliki nilai simpangan baku relatif (%SBR) sebesar 2.14% dan 2.44%, berturut-turut untuk kuersetin dan rutin. Hal ini menunjukkan bahwa SPCE termodifikasi grafena cukup potensial untuk deteksi simultan kuersetin dan rutin secara elektrokimia. Kata kunci: Grafena, kuersetin, rutin, screen printed carbon electrode, voltametri siklik. Quercetin and rutin are natural antioxidant from flavonoid group. The compounds can be detected using several analytical technique, including electrochemical technique due to its redox activity. In this study, simultaneous detection of quercetin and rutin was performed at graphene-modified screen printed carbon electrode (SPCE) using cyclic voltammetry technique. Graphene-modified SPCE was prepared from mixture of graphene:sodium polyacrylate (1:1) via drop casting method. Ethanol 70%:phosphate bufer pH 7 (6:4) was used as electrolyte solution for quercetin and rutin measurement. The result shows that oxidation peak of quercetin and rutin was detected at potential of 0.179 V and 0.310 V vs Ag/AgCl, respectively. Graphene-modified SPCE produce higher intensity of oxidation current and higher sensitivity for quercetin and rutin measurement. Simultaneous detection of quercetin and rutin at graphene modified SPCE provide linearity with R2 = 0.9905 and R2 = 0.9816, respectively for quercetin and rutin. Detection limits of quercetin and rutin respectively was 0.5369 mM and 0.7495 mM while limit quantitation was 1.7898 mM dan 2.4985 mM. Precision of quercetin and rutin measurement was moderate with percent relative standard deviation (%RSD) of 2.14% and 2.44%, consecutively for quercetin and rutin. This suggests that graphene-modified SPCE is potential for simultaneous electrochemical detection of quercetin and rutin. Keywords: Cyclic voltammetry, graphene, quercetin, rutin, screen printed carbon electrode.