An efficient chitosan-naphthalimide fluorescent probe for simultaneous detection and adsorption of Hg2+ and its application in seafood, water and soil environments

Graphene oxide supported MOFs-nanofiber carbon aerogel/SPCE for simultaneous detection of Cd2+ and Pb2+ in seafood

A novel electrochemical sensor for detecting heavy metal ions in seafood was developed to address food safety concerns. The sensor integrates graphene oxide into NH2-UiO-66 loaded nanofiber carbon aerogel, enhanced its three-dimensional conductive network and effective active surface area (0.34 cm2), which improved ion enrichment and oxidation-reduction reaction rates. Using the Box-Behnken design, the sensor was optimized to detect cadmium and lead with LODs of 0.16 μg·L-1 and 0.07 μg·L-1 in the 1 to 150 μg·L-1 linear range. Applied to real seafood samples, the sensor showed results consistent with ICP-OES, confirmed its reliability in complex substrates. This approach offered a promising, low-cost solution for real-time monitoring of heavy metal contamination in seafood, ensuring public food safety.

A dual-functional specific fluorescent bio-sensor based on triphenylamine for "turn-off" recognition of copper and mercury: Application in real samples and living system

Accurately monitoring the content of Cu2+ and Hg2+ in real samples and biological systems is of great significance in ensuring food safety and human health. Therefore, developing efficient methods for simultaneously detecting Cu2+ and Hg2+ is of great significance in living organisms and real samples. In this work, a bifunctional ratiometric and colorimetric fluorescent bio-sensor DPT-1, was designed and synthesized using triphenylamine to specifically and concurrently detect Cu2+ and Hg2+ exhibited varying degrees of fluorescence quenching through "turn-off" fluorescence. Furthermore, DPT-1 effectively detected Cu2+ and Hg2+ in various real samples, encompassing tap water, Songhua River water, and honeysuckle extract. In addition, DPT-1 exhibited remarkable performance in detecting Cu2+/Hg2+ in rice roots, living cells and zebrafish. As research progressed, the discoveries outlined in this article offered the versatile potential for holding promise for food safety monitoring and biological research.

A Rhodamine-based high-sensitivity low-cytotoxicity probe for rapid turn-on detection of Hg2

By integrating Rhodamine B and 4-phenylmorpholine moieties, a novel fluorescent probe named RhPy is synthesized for detecting Hg2+. Its recognition mechanism involves the reaction of Hg2+ with dithiooxamide, ultimately triggering the opening of the Rhodamine spirolactam and forming a new molecule RhPy-S with strong emission. The probe exhibits impressive limit of detection (0.015 μM) and short response time (<10 s). Importantly, RhPy shows almost none-cytotoxicity and RhPy-S has the emission spectrum peaking at 596 nm, which endow the probe with a good tissue penetration ability and practical utility in living cells, zebrafish and in vivo mice models. This work advances the field by providing a highly sensitive chemosensor for both environmental and biological applications.

Fluorescent chemosensors facilitate the visualization of plant health and their living environment in sustainable agriculture

Globally, 91% of plant production encounters diverse environmental stresses that adversely affect their growth, leading to severe yield losses of 50-60%. In this case, monitoring the connection between the environment and plant health can balance population demands with environmental protection and resource distribution. Fluorescent chemosensors have shown great progress in monitoring the health and environment of plants due to their high sensitivity and biocompatibility. However, to date, no comprehensive analysis and systematic summary of fluorescent chemosensors used in monitoring the correlation between plant health and their environment have been reported. Thus, herein, we summarize the current fluorescent chemosensors ranging from their design strategies to applications in monitoring plant-environment interaction processes. First, we highlight the types of fluorescent chemosensors with design strategies to resolve the bottlenecks encountered in monitoring the health and living environment of plants. In addition, the applications of fluorescent small-molecule, nano and supramolecular chemosensors in the visualization of the health and living environment of plants are discussed. Finally, the major challenges and perspectives in this field are presented. This work will provide guidance for the design of efficient fluorescent chemosensors to monitor plant health, and then promote sustainable agricultural development.

Chitosan-based fluorescent probe for the detection of Fe3+ in real water and food samples

Iron ions play a crucial role in the environment and the human body. Therefore, developing an effective detection method is crucial. In this paper, we report CNS2, a chitosan-based fluorescent probe utilizing naphthalimide as a fluorophore. CNS2 is designed to "quench" its own yellow fluorescence through the specific binding of compounds containing enol structures to Fe3+. Studying the fluorescence lifetime of CNS2 in the presence or absence of Fe3+ reveals that the quenching mechanism is static. The presence of multiple recognition sites on the chitosan chain bound to Fe3+ gave CNS2 rapid recognition (1 min) and high sensitivity, with a detection limit as low as 0.211 μM. Moreover, the recognition of Fe3+ by CNS2 had a good specificity and was not affected by interferences. More importantly, in this study, CNS2 was successfully utilised to prepare fluorescent composite membranes and to detect Fe3+ in real water samples and a variety of food samples. The results show that the complex sample environment still does not affect the recognition of Fe3+ by CNS2. All the above experiments obtained more satisfactory results, which provide strong support for the detection of Fe3+ by the probe CNS2 in practical applications.