Micrometer-level naked-eye detection of caesium particulates in the solid state

Abstract

Large amounts of radioactive material were released from the Fukushima Daiichi nuclear plant in Japan, contaminating the local environment. During the early stages of such nuclear accidents, iodine I-131 (half-life 8.02 d) is usually detectable in the surrounding atmosphere and bodies of water. On the other hand, in the long-term, soil and water contamination by Cs-137, which has a half-life of 30.17 years, is a serious problem. In Japan, the government is planning and carrying out radioactive decontamination operations not only with public agencies but also non-governmental organizations, making radiation measurements within Japan. If caesium (also radiocaesium) could be detected by the naked eye then its environmental remediation would be facilitated. Supramolecular material approaches, such as host–guest chemistry, are useful in the design of high-resolution molecular sensors and can be used to convert molecular-recognition processes into optical signals. In this work, we have developed molecular materials (here, phenols) as an optical probe for caesium cation-containing particles with implementation based on simple spray-on reagents and a commonly available fluorescent lamp for naked-eye detection in the solid state. This chemical optical probe provides a higher spatial resolution than existing radioscopes and gamma-ray cameras.

Direct Integration of Red‐NIR Emissive Ceramic‐like AnM6Xi8Xa6 Metal Cluster Salts in Organic Copolymers Using Supramolecular Interactions

“…A similar approach was used by Mori et al. in Japan to develop Cs molecular sensors after the Fukushima Daiichi nuclear disaster …”

Nanoarchitectonic‐Based Material Platforms for Environmental and Bioprocessing Applications

“…In light of the accident at the Fukushima Daiichi nuclear power plant, these nanoarchitectonic‐based sensing platforms could potentially fill important needs to monitor the distribution of radioactive species, including 137 Cs, in the environment. In order to visually detect Cs ions in the environment, a novel reagent called Cesium Green has been developed . The presence of Cs ions in contaminated ground and within plant cells can be sensed by the bright fluorescence arising from the specific interaction between Cs ion and Cesium Green .…”

Nanophotonics and supramolecular chemistry

“…The host molecule used for this purpose was 1-(4′-hydroxy phenyl)-4-phenylbenzene connected to a 4-nitrophenyl ether group through a tetraethylene glycol linker separating the two aromatic moieties ( Figure 5) [64]. Caesium cation-containing particles can be visualized after spraying with this host molecule in methanol, which is especially suitable for detecting caesium salts in particulate form and promotes the ability to detect them with the naked eye in the solid state.…”