Overview of ion chromatographic applications for the analysis of nuclear materials: Case studies

Abstract Accurate, precise, and rapid analytical monitoring of various nuclear materials is essential for the smooth functioning of nuclear reactors. Ion chromatography (IC) has emerged as an effective analytical tool for simultaneous detection of different ions in a wide range of materials used in the nuclear industry. The major advantages over other techniques include superior selectivity and sensitivity for detection of anions and cations, wide dynamic range, and speciation studies of ions. This article provides an overview of different ion chromatographic methodologies developed for the analyses of various nuclear materials such as fuel, control rods, moderator, coolant, and process streams. Comparison of various analytical aspects of IC over the other routine techniques reveals the ease and multidimensional capability of the technique. An insight is given to the modern variations in the field such as coupling of IC with other techniques for the characterization of nuclear matrices, implementation of capillary IC in terms of miniaturization, and so on. The information presented herein will serve as a very useful resource for investigators in the field of characterization of nuclear materials.</jats:p

A gold nanorod-based optical DNA biosensor for the diagnosis of pathogens

A novel optical biosensor for detecting target DNA, utilizing gold nanorods (GNRs) as molecular probes is demonstrated. This sensor is based on simultaneous biorecognition-mediated hybridization of target DNA in a sandwich type manner with two different capture probe DNA sequences modified separately with identical sets of GNRs, which leads to aggregation of GNRs. The hybridization induced aggregation as revealed by TEM analysis, promotes the modulation of surface plasmon resonance of GNRs, which forms the basis of complementary target DNA detection from the Chlamydia trachomatis pathogen. Thermally induced reversible dissociation of hybridized DNA is demonstrated by melting analysis. The present sensing strategy is successfully demonstrated by detecting PCR amplified C. trachomatis pathogen gene isolated from human urine sample in a concentration range of 0.25-20 nM. Furthermore, this sensor displays excellent specificity by discriminating the target DNA versus other non-specific pathogenic genes. (C) 2010 Elsevier B.V. All rights reserved.This work was supported by National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2009-0080602 and No.R01-2007-000-11851-0) and Brain Korea 21 (BK21) program.