Determination of Yeast RNA Using Safranine T with Linear Sweep Voltammetry

Wei Sun*, Na Zhao, Kui Jiao
College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, P. R.China
Tel: +86-532-4022681, Fax: +86-532-4023927,
E-mail: sunwei@qust.edu.cn

Abstract
A new linear sweep voltammetric method was developed for the determination of trace amount of yeast RNA (yRNA) by using safranine T (ST) as an electrochemical probe. In a pH 3.5 Britton-Robinson (B-R) buffer solution, ST had a sensitive linear sweep voltammetric reduction peak at –0.39 V (νs. SCE) and the addition of yRNA can decrease the reduction peak current of ST without the shift of the peak potential. The decrease of the peak current was proportional to the concentration of yRNA and further used for yRNA determination. The optimum conditions for the determination of yRNA were investigated. Under the optimal conditions a linear relationship of the peak current with the concentration of yRNA was got in the range of 8.0–25.0 mg L^–1 with the detection limit as 0.84 mg L^–1. The method was simple, practical and free of the interferences from coexisting substances. Three synthetic samples were analyzed with satisfactory results. The binding constant ( β_s) and the binding number (m) of yRNA with ST was calculated by voltammetric method with the results as β_s = 1.05 × 10¹¹ and m = 2.5.

Keywords: Yeast RNA, safranine T, linear sweep voltammetry, interaction