The Fabrication of a La2Sn2O7/f-HNT Composite for Non-Enzymatic Electrochemical Detection of 3-Nitro-l-tyrosine in Biological Samples.

Reactive oxygen and nitrogen species (RONS), including 3-nitro-l-tyrosine, play a dual role in human health, inducing oxidative damage and regulating cellular functions. Early and accurate detection of such molecules, such as L-tyrosine in urine, can serve as critical biomarkers for various cancers. In this study, we aimed to enhance the electrochemical detection of these molecules through the synthesis of La2Sn2O7/f-HNT nanocomposites via a simple hydrothermal method. Detailed structural and morphological characterizations confirmed successful synthesis, consistent with our expected outcomes. The synthesized nanocomposites were utilized as nanocatalysts in electrochemical sensors, showing a notable limit of the detection of 0.012 µM for the real-time detection of 3-nitro-l-tyrosine. These findings underscore the potential of nanomaterial-based sensors in advancing early disease detection with high sensitivity, furthering our understanding of cellular oxidative processes.

Highly sensitive determination of cancer toxic mercury ions in biological and human sustenance samples based on green and robust synthesized stannic oxide nanoparticles decorated reduced graphene oxide sheets.

This work proposes the conventional sonochemical synthesis of nanoparticles of tin (IV) oxide on reduced graphene oxide (rGOS@SnO2) influencing the formation of a composite with enhanced properties. The combination of SnO2 nanoparticles with rGOS weakens the accumulation in layered structures of the latter system, which leads to better exposure of SnO2 active sites and thus increases the conductivity of rGOS@SnO2 composite. This validates the improved electro-catalytic activity of the composite based on previous reports for its successful utilization in the electrochemical determination of toxic contaminants. The quantitative determination of mercury ions, through the use of the electrochemical sensor based on rGOS@SnO2 manifests several advantages such as simple operator, promptness, cost effectiveness and time independency when compared to other traditional techniques. The fabricated sensor displays two wide linear responses in the range of 0.25-705.3 µM for mercury ions, with a rapid response time about 1 s, and with a high sensitivity of 10.18 µA µM-1 cm-2 under optimized conditions. The accumulation of traces of mercury in the bodies of fish in the marine eco system marks the significance of its detection in real samples. The satisfactory results of the proposed sensor establish the supreme efficacy of layered nanomaterials in conjunction with nanoparticles for the simple, rapid and efficient detection of pollutants in food and biological samples.