Trace Determination of DNA in an Amaryllidaceae Plant, Narcissus tazetta by Squarewave Stripping Voltammetry Based on Guanine Signal
Yavuz YARDIM*, Zühre ŞENTÜRK*,°, Mehmet ÖZSÖZ**, Kerem ÖZDEMİR***, Ekrem ATALAN***
*Yüzüncü Yıl University, Faculty of Science and Letters, Department of Analytical Chemistry, 65080 Van, Turkey
**Ege University, Faculty of Pharmacy, Department of Analytical Chemistry, 35100 İzmir, Turkey
***Yüzüncü Yıl University, Faculty of Science and Letters, Department of General Biology, 65080 Van, Turkey

° Corresponding author e-mail: zuhresenturk@hotmail.com

Summary

This study is, to our knowledge, the first application of electrochemical DNA biosensor for the quantification of DNA in plant extracts. The DNA biosensor was assembled by immobilizing the double-stranded fish sperm DNA on the surface of a singleuse pencil graphite electrode. Square-wave voltammetric method with the baseline correction was carried out to evaluate the oxidation signal of the guanine base. The experimental variables such as solution pH, buffer concentration, immobilization time, stirring speed, and square-wave parameters were optimized. The extremely low detection limit (0.36 ng/mL) was coupled to a good surface-to-surface reproducibility (a relative standard deviation of 8.4% for 7 repetitive measurements of 40 ng/mL). The renewable and low-cost DNA biosensor developed in this study using pencil graphite electrode was applied to the determination of DNA isolated from an Amaryllidaceae plant, Narcissus tazetta.

Key Words :
Electrochemical DNA biosensor, pencil graphite electrode, square-wave stripping voltammetry, plant samples, Narcissus tazette subsp. tazetta.