Novel nanosensor of cobalt(II) and copper(II) constructed from graphene quantum dots modified with Eriochrome Black T

Symmetrical Ligand's Fabricated Porous Silicon Surface Based Photoluminescence Sensor for Metal Detection and Entrapment

This study was based on the development of surface-based photoluminescence sensor for metal detection, quantification, and sample purification employing the solid sensory chip having the capability of metal entrapment. The Co(II), Cu(II) and Hg(II) sensitive fluorescence sensor (TP) was first synthesized and characterized its sensing abilities towards tested metal ions by using fluorescence spectral investigation while the synthesis and complexation of the receptor was confirmed by the chromogenic, optical, spectroscopic and spectrometric analysis. Under optical investigation, the ligand solution exhibited substantial chromogenic changes as well as spectral variations upon reacting with copper, cobalt, and mercuric ions, while these behaviors were not seen for the rest of tested metallic ions i.e., Na+, Ag+, Ni2+, Mn2+, Pd2+, Pb2+, Cd2+, Zn2+, Sn2+, Fe2+, Fe3+, Cr3+, and Al3+. These colorimetric alterations and spectral shifting could potentially be employed to detect and quantify these specific metal ions. After the establishment of the ligand's selective complexation ability towards selected metals, it was fabricated over the substituted porous silicon surface (FPS) keeping in view of the development of surface-based photoluminescence sensor (TP-FPS) for the selected metal sensation and entrapment to purify the sample just be putting off the metal entrapped sensory solid chip. Surface characterization and ligand fabrication was inspected by plan and cross sectional electron microscopic investigations, vibrational and electronic spectral analysis. The sensitivity of the ligand (TP) in the solution phase metal discrimination was determined by employing the fluorescence titration analysis of the ligand solution after progressive induction of Co2+, Cu2+, and Hg2+, which afford the detection limit values of 2.14 × 10- 8, 3.47 × 10- 8 and 3.13 × 10- 3, respectively. Concurrently, photoluminescence titration of the surface fabricated sensor (TP-FPS) revealed detection limit values of 3.14 × 10- 9, 7.43 × 10- 9, and 8.21 × 10- 4, respectively, for the selected metal ions.

Ratiometric Fluorescence and Chromogenic Probe for Trace Detection of Selected Transition Metals

The design and development of a fluorescence sensor aimed at detecting and quantifying trace amounts of toxic transition metal ions within environmental, biological, and aquatic samples has garnered significant attention from diagnostic and testing laboratories, driven by the imperative to mitigate the health risks associated with these contaminants. In this context, we present the utilization of a heterocyclic symmetrical Schiff Base derivative for the purpose of fluorogenic and chromogenic detection of Co2+, Cu2+ and Hg2+ ions. The characterization of the ligand involved a comprehensive array of techniques, including physical assessments, optical analyses, NMR, FT-IR, and mass spectrometric examinations. The mechanism of ligand-metal complexation was elucidated through the utilization of photophysical parameters and FT-IR spectroscopic analysis, both before and after the interaction between the ligand and the metal salt solution. The pronounced alterations observed in absorption and fluorescence spectra, along with the distinctive chromogenic changes, following treatment with Co2+, Cu2+ and Hg2+, affirm the successful formation of complexes between the ligands and the treated metal ions. Notably, the receptor's complexation response exhibited selectivity towards Co(II), Cu(II), and Hg(II), with no observed chromogenic changes, spectral variations, or band shifts for the various tested metal ions, including Na+, Ag+, Ni2+, Mn2+, Pd2+, Pb2+, Cd2+, Zn2+, Sn2+, Fe2+, Fe3+, Cr3+ and Al3+. This absence of interaction between these metal ions and the ligand could be attributed to their compact or inadequately conducive conduction bands for complexation with the ligand's structural composition. To quantify the sensor's efficacy, fluorescence titration spectra were employed to determine the detection limits for Co2+, Cu2+ and Hg2+, yielding values of 2.92 × 10-8, 8.91 × 10-8, and 4.39 × 10-3 M, respectively. The Benesi-Hildebrand plots provided association constant values for the ligand-cobalt, ligand-copper, and ligand-mercury complexes as 0.74, 2.52, and 13.89 M-1, respectively.

Anti-Cancer Potency of Copper-Doped Carbon Quantum Dots Against Breast Cancer Progression

Introduction

The anti-cancer potency of copper-doped carbon quantum dots (Cu-CDs) against breast cancer progression needs more detailed investigations.

Methods

With urea and ethylene glycol applied as carbon sources and copper sulfate used as a reactive dopant, Cu-CDs were synthesized in the current study by a one-step hydrothermal synthesis method, followed by the characterization and biocompatibility evaluations of Cu-CDs. Subsequently, the anti-cancer potency of Cu-CDs against breast cancer progression was confirmed by these biochemical, molecular, and transcriptomic assessments, including viability, proliferation, migration, invasion, adhesion, clonogenicity, cell cycle distribution, apoptosis, redox homeostasis, and transcriptomic assays of MDA-MB-231 cells.

Results

The biocompatibility of Cu-CDs was confirmed based on the non-significant changes in the pathological and physiological parameters in the Cu-CDs treated mice, as well as the noncytotoxic effect of Cu-CDs on normal cells. Moreover, the Cu-CDs treatments not only decreased the viability, proliferation, migration, invasion, adhesion, and clonogenicity of MDA-MB-231 cells but also induced the redox imbalance, cell cycle arrest, and apoptosis of MDA-MB-231 cells via ameliorating the mitochondrial dysfunctions and regulating the MAPK signaling pathway.

Conclusion

Our findings confirmed the biosafety and excellent anti-cancer potency of Cu-CDs against breast cancer progression by tapping into mechanisms that disrupt malignant behaviors and oxidative homeostasis of breast cancer cells.

Quantum mechanisms for selective detection in complex gas mixtures using conductive sensors

In this paper, we consider new quantum mechanisms for selective detection in complex gaseous media which provide the highest possible efficiency of quantum sensors and for the first time analyze their nature. On the basis of these quantum mechanisms, the concepts of quantum detection and innovative methods of analysis are developed, which are virtually impossible to implement in the conventional conductive sensors and nanosensors. Examples of original solutions to problems in the field of detection and analysis of human breath using point-contact sensors are considered. A new method of analysis based on detection of metastable quantum states of the "point-contact sensor-breath" system in dynamic mode is proposed. The conductance histogram of dendritic Yanson point contacts recorded for this system is a unique energy signature of breath which allows differentiation between the states of human body. We demonstrate that nanosized Yanson point contacts, which, thanks to their quantum properties, can replace a massive spectrometer, open up wide opportunities for solving complex problems in the field of breath analysis using a new generation of portable high-tech quantum sensor devices.