Development of the simple analytical method for determination of arsenate(V) ion using fluorescence-labeled DNA and cerium oxide nanoparticles

Abstract

Abstract Arsenic (As) contamination in groundwater presents a major health and environmental concern. As is found in two oxidation states and most chemical tests for inorganic arsenic are focused on As(III), and few have been developed for As(V). We developed the simple analytical method for determining As(V) concentrations in groundwater using CeO2NPs and fluorescein (FAM)-labeled DNA. Prior to sample measurements, we investigated the key operational parameters that affect the sensing performance. The optimal CeO2NPs final concentration, FAM-labeled DNA final concentration, the sequence and length of FAM-labeled DNA, and incubation time were 15 μg/mL, 400 nM, 6-mer poly-cytosine sequence, and 6 min, respectively. After optimizing the parameters, the total analysis time was about 20 min and the limit of detection was 0.61 μM. This method has a high selectivity against the same concentrations of Cu(II), Cd(II), Hg(II) and Pb(II). Pretreatment by cation extraction to remove interfering ions was beneficial for determination of As(V) concentrations in groundwater containing a variety of metal cations at high concentration. We could determine As(V) concentration in groundwater. Modification of the reactions of the method is necessary. This study provides the first step in the development of a simple method for on-site As(V) analysis.