Visual and Real-Time Monitoring of Cd²⁺ in Water, Rice, and Rice Soil with Test Paper Based on [2 + 2] Lanthanide Clusters

Abstract

Cadmium ions (Cd2+) are highly toxic to animal and human health, especially through the drinking of Cd2+-contaminated water and eating Cd2+-contaminated rice. Therefore, accurate detection of Cd2+ in water, rice, and rice soil is urgent. In this work, two [2 + 2] lanthanide clusters of Tb2Tb2 and Eu2Eu2 were synthesized and characterized in detail. Interestingly, Tb2Tb2 is a rapid sensor for Cd2+ through luminescence “turn-off”. Further studies show that Tb2Tb2 is a highly sensitive and selective sensor toward Cd2+ in water, rice supernatants, and rice soil supernatants, with a very short response time of 20 s. The limit of detection (LOD) in the above three real samples is as low as 0.0112, 1.1240, and 0.1124 ppb, respectively, which is lower than the national standards for food safety in China (GB 2762-2022). More interestingly, a portable sensing device of test paper based on Tb2Tb2 is developed with a facile method, which shows visible, highly sensitive, and selective sensing toward Cd2+ in real samples of water, rice supernatants, and rice soil supernatants. Tb2Tb2 and its sensing device of test paper are an on-site analysis sensor for potentially non-expert users, especially for people in remote rural areas.

Tetra-Nuclear Cluster-Based Lanthanide Metal–Organic Frameworks as White Phosphor, Information Encryption, Self-Calibrating Thermometers, and Fe2+ Sensors

“…Single crystals of TbMOF , EuMOF , Tb,EuMOF , and ligands were selected and photographed under the daylight and 365 nm ultraviolet (UV) light; they are transparent under the daylight (Figure S11a–c), and luminescence microscopy reveals that they show green, red, and orange-yellow light under 365 nm UV light, respectively (Figure S11a′–c′). However, the ligands of H 2 BTDB and GdMOF are transparent (Figure S11d,e) and show no luminescence under 365 nm UV light.…”

Sustainable Sensing with Paper Microfluidics: Applications in Health, Environment, and Food Safety

“…Integrating FRET technology into a paper-based platform enhances the efficiency and throughput of the aptasensor, offering a versatile and sensitive tool for rapid detection in diverse sample matrices. Yu et al [ 188 ] introduced a fiber-made filter-paper-based device for the real-time monitoring of Cd 2+ in water, rice, and rice soil (see Figure 8 b). The developed test paper exhibited highly sensitive and visible sensing capabilities for Cd 2+ in water, rice supernatants, and rice soil supernatants.…”

“…©2022 Elsevier B.V. ( b ) Schematics of fiber-made filter-paper-based biosensors for the real-time monitoring of Cd 2+ in water, rice, and rice soil. Reprinted with permission from Yu et al [ 188 ]. ©2023 American Chemical Society.…”

Sustainable Sensing with Paper Microfluidics: Applications in Health, Environment, and Food Safety

“…Integrating FRET technology into a paper-based platform enhances the efficiency and throughput of the aptasensor, offering a versatile and sensitive tool for rapid detection in diverse sample matrices. Yu et al [178] introduced a fiber-made filter paper-based device for the real-time monitoring of Cd 2+ in water, rice, and rice soil (see Figure 7(b)). The developed test paper exhibited highly sensitive and visible sensing capabilities for Cd 2+ in water, rice supernatants, and rice soil supernatants.…”