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

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 CeO(2)NPs and fluorescein (FAM)-labeled DNA. Prior to sample measurements, we investigated the key operational parameters that affect the sensing performance. The optimal CeO2 NPs final concentration, FAM-labeled DNA final concentration, the sequence and length of FAM-labeled DNA, and incubation time were 15 mu g/mL, 400 nM, 6-mer polycytosine 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 mu M. 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.

Automated summary

In this study, a simple analytical method using CeO(2)NPs and FAM-labeled DNA was developed to determine As(V) concentrations in groundwater. After optimizing the parameters, the total analysis time was about 20 min and the limit of detection was 0.61 μM. The method showed high selectivity against other metal ions.