Ag@CDs nanohybrid: Fabrication, design of a multi-mode chemosensory probe for selective Fe3+ detection and logic gate operation

Dual-mode fluorimetric and colorimetric sensors based on iron and nitrogen co-doped carbon dots for the detection of dopamine

Determination of dopamine (DA) is crucial for its intimate relationship with clinical trials and biological environment. Herein, Fe, N co-doped carbon dots (AFC-CDs) were fabricated by optimizing precursors and reaction conditions for fluorimetric/colorimetric dual-mode sensing of DA. With synergistic influence of Förster resonance energy transfer and static quenching effect, DA significantly quenched the blue luminescence of AFC-CDs at 442 nm, the production of recognizable tan-brown complex caused evident colorimetric response, achieved the dual-mode fluorimetric/colorimetric sensing for DA. The excellent selectivity and satisfied sensitivity can be confirmed with the limit of detection at 0.29 μM and 2.31 μM via fluorimetric/colorimetric mode respectively. The reliability and practicability were proved by recovery of 94.81-101.61% in real samples. Notably, the proposed electron transfer way between AFC-CDs and DA was hypothesized logically, indicated dual-mode probe provided a promising platform for the sensing of trace DA, and could be expanded in environment and food safety.

Carbon and graphene quantum dots based architectonics for efficient aqueous decontamination by adsorption chromatography technique - Current state and prospects

Aquatic ecosystems and potable water are being exploited and depleted due to urbanization and the encouragement of extensive industrialization, which induces the scarcity of pure water. However, current decontamination methods are limited and inefficient. Various innovative remediation strategies with novel nanomaterials have recently been demonstrated for wastewater treatment. Carbon dots (C-dots) and graphene quantum dots (GQ-dots) are the most recent frontiers in carbon nanomaterial-based adsorption studies. C-dots are extremely small (1-10 nm) quasi-spherical carbon nanoparticles (mostly sp3 hybridized carbon), whereas GQ-dots are fragments of graphene (1-20 nm) composed of primarily sp2 hybridized carbon. This article highlights the function of C-dots and GQ-dots with their specifications and characteristics for the efficient removal of organic and inorganic contaminants in water via adsorption chromatography. The alteration of adsorption attributes with the hybrid blending of these dots has been critically analyzed. Moreover, various top-down and bottom-up approaches for synthesizing C-dots and GQ-dots, which ultimately affect their morphology and structure, are described in detail. Finally, we review the research deficit in the adsorption of diverse pollutants, fabrication challenges, low molecular weight, self-agglomeration, and the future of the dots by providing research prospects and selectivity and sensitivity perspectives, the importance of post-adsorption optimization strategies and the path toward scalability at the tail of the article.

Biocompatibility assessment of bovine serum albumin conjugated manganese dioxide nanoparticle and their therapeutic role against microwave radiation induced haematological toxicity in male Wistar rats

Microwave (MW) radiations are widely used in communications, radar and medical treatment and thus human exposure to MW radiations have increased tremendously, raising health concerns as MW has been implicated in induction of oxidative stress condition in our body. Few metallic nanoparticles (NPs) have been shown to mimic the activity of antioxidant enzymes and hence can be applied for the modulation of adverse effects caused by MW. Present study aimed to assess the biocompatibility of Bovine serum albumin (BSA) conjugated manganese dioxide nanoparticles (MNP*) and to counteract the impact of MW on the haematological system of male Wistar rats. Experiments were conducted in two sets. Set I involved biodistribution and antioxidant activity evaluation of MNP* at different doses. Results showed a dose-dependent increase in antioxidant potential and significant biodistribution in the liver, spleen, kidney, and testis, with no organ damage, indicating its biocompatibility. Experiment set II constituted the study of separate and combined effects of MW and MNP* on haematological parameters, oxidative status, and genotoxic study in the blood of rats. MW exposure significantly altered red blood cell count, hemoglobin, packed cell volume percentage, monocyte percentage, aspartate aminotransferase, Alanine aminotransferase and uric acid. MW also induced significant DNA damage in the blood. A significant increase in lipid peroxidation and a decrease in antioxidant enzyme superoxide dismutase was also observed in MW exposed group. However, these alterations were reduced significantly when MNP* was administered. Thus, MNP* showed biocompatibility and modulatory effects against MW-induced alterations in the haematological system of rats.

Emerging pollutants in etiology and pathophysiology of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a multifactorial endocrine disorder affecting reproductive-aged women worldwide. Although genetic and lifestyle factors have been implicated in its etiology, emerging evidence suggests that exposure to environmental pollutants may also contribute significantly to the development and pathophysiology of PCOS. This review article aims to provide a comprehensive overview of the potential role of emerging pollutants, including pharmaceuticals and personal care products (PPCPs), microplastics, endocrine disruptors, and nanoparticles, in PCOS development. The article summarizes the current understanding of PCOS pathogenesis and its clinical manifestations. Subsequently, it delves into the mechanisms of action of the emerging pollutants, exploring how they may disrupt the endocrine system, interfere with hormonal regulation, and contribute to the manifestation of PCOS symptoms. Moreover, the potential for cumulative effects and synergistic interactions between these pollutants demands a cautious approach when considering their role in PCOS etiology.

Biogenic carbon dots: a novel mechanistic approach to combat multidrug-resistant critical pathogens on the global priority list

This study delves into investigating alternative methodologies for anti-microbial therapy by focusing on the mechanistic assessment of carbon dots (CDs) synthesized from F. benghalensis L. extracts. These biogenic CDs have shown remarkable broad-spectrum anti-bacterial activity even against multi-drug resistant (MDR) bacterial strains, prompting a deeper examination of their potential as novel anti-microbial agents. The study highlights the significant detrimental impact of CDs on bacterial cells through oxidative damage, which disrupts the delicate balance of ROS control within the cells. Notably, even at low doses, the anti-bacterial activity of CDs against MDR strains of P. aeruginosa and E. cloacae is highly effective, demonstrating their promise as potent antimicrobial agents. The research sheds light on the capacity of CDs to generate ROS, leading to membrane lipid peroxidation, loss of membrane potential, and rupture of bacterial cell membranes, resulting in cytoplasmic leakage. SEM and TEM analysis revealed time-dependent cell surface, morphological, and ultrastructural changes such as elongation of the cells, irregular surface protrusion, cell wall and cell membrane disintegration, internalization, and aggregations of CDs. These mechanisms offer a comprehensive explanation of how CDs exert their anti-bacterial effects. We also determined the status of plasma membrane integrity and evaluated live (viable) and dead cells upon CD exposure by flow cytometry. Furthermore, comet assay, biochemical assays, and SDS PAGE identify DNA damage, carbohydrate and protein leakage, and distinct differences in protein expression, adding another layer of understanding to the mechanisms behind CDs' anti-bacterial activity. These findings pave the way for future research on managing ROS levels and developing CDs with enhanced anti-bacterial properties, presenting a breakthrough in anti-microbial therapy.

Emission enhanced fluorometric biosensor by functionalized carbon polymer dots for glutathione detection in human real samples and molecular logic gate operation

Glutathione (GSH), an active peptide, plays pivotal roles in many physiological processes and detection of GSH inside of human body is of great importance for the playing of its biological effects. Here silver-phosphorus co-doped carbonized polymer dots (Ag@PCPDs) were prepared via solvothermal treatment of citric acid and phytic acid in the presence of Ag+ for GSH determination. The physicochemical and optical performance of the Ag@PCPDs were characterized by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FT-IR), X-ray powder diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), fluorescence spectroscopy and ultraviolet-visible (UV-Vis) spectroscopy analyses. The prepared Ag@PCPDs have outstanding water solubility with high monodispersity (7.81 ± 0.31 nm) and exhibited excellent optical properties with excitation-dependent emission, high photostability, pH, and ionic strength tolerance. An optimized excitation at 358 nm, the Ag@PCPDs showed strong photoluminescent (PL) emission at 456 nm with a PL quantum yield (QYs) of 15.6%. Furthermore, the Ag@PCPDs were used as a PL sensing platform for detection GSH in a linear range of 0-200 μM with a low limit of detection at 0.68 μM. In addition, the proposed system can construct molecular logic gates with GSH and Fe3+ ions as the chemical inputs and PL emissions as the output. And the Ag@PCPDs were successfully used for GSH determination in real samples resulting in high sensitivity and satisfactory recoveries (92.81--107.45%). More importantly, the Ag@PCPDs showed low cytotoxicity at 500 μg/mL and superior cell imaging capability in HeLa cells, which offer a new path for detection and categorization of GSH in biomedical applications.

Nanoclusters with specific DNA overhangs: modifying configurability, engineering contrary logic pairs and the parity generator/checker for error detection

The most promising alternative for next-generation molecular computers is biocomputing, which uses DNAs as its primary building blocks to perform a Boolean operation. DNA nanoclusters (NCs) have emerged as promising candidates for biosensing applications due to their unique self-assembly properties and programmability. It has been demonstrated that adding DNA overhangs to DNA NCs improves their adaptability in identifying specific biomolecular interactions. A recent proposal in DNA computing is the concept of "contrary logic pairs (CLPs)" executed by employing a DNA hybrid architecture as a universal platform. We have designed thymine overhang-modified DNA-templated NCs (T-Au/Ag NCs). These NCs serve as a chemosensing ensemble platform, where the presence of HgII ions mediates the formation of M-Au/Ag NCs. The resulting NCs exhibit the capability to drive elementary CLPs (YES, NOT, OR, NOR, INH and IMP) as well as complex logic operations (XOR and XNOR). Additionally, they can be utilized for advanced non-arithmetic DNA logic devices like a parity generator (pG) and a parity checker (pC) for "error detection". Bit errors are an unavoidable and common occurrence during any computing. A cascade of XOR operations was used to evaluate these errors by introducing the pG and pC at the transmitting (TX) and receiving (RX) ends in binary transmission, respectively, which has devastating implications for reliable logic circuits, especially in advanced logic computation. Moreover, an even/odd natural number from 0 to 9 distinguishable pC was designed based on a dual-source responsive computing platform. This work offers inspiring avenues for a cost-effective strategy to construct highly-intelligent DNA computing devices by enhancing the multi-input responsive single DNA platform concept.

Colorimetric sensor based on biogenic nanomaterials for high sensitive detection of hydrogen peroxide and multi-metals

Hydrogen peroxide (H2O2) and heavy metals, which are among the wastes of the industrial sector, become a threat to living things and the environment above certain concentrations. Therefore, the detection of both H2O2 and heavy metals with simple, low-cost, and fast analytical methods has gained great importance. The use of nanoparticles in colorimetric sensor technology for the detection of these analytes provides great advantages. In recent years, green synthesis of nanomaterials with products that can be considered biowaste is among the popular topics. In this study, silver/silver chloride nanoparticles (Ag@AgCl NPs) were synthesized using the green synthesis method as an eco-friendly and cheap method, the green algae extract was used as a reducing agent. The characterization of Ag@AgCl nanoparticles and green algae extract was carried out with several techniques such as Transmission Electron Microscopy (TEM), UV-Visible spectrometry (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction patterns (XRD) methods were used for characterization. According to TEM analysis, the Ag@AgCl NPs typically spherical in form and range in size from 4 to 10 nm, and UV-vis showed the formation of surface plasmon resonance (SPR) of the Ag@AgCl between 400 and 450 nm. In addition, its activity as a colorimetric sensor for hydrogen peroxide (H2O2) and multi-metal detection was evaluated. Interestingly, Ag/AgCl NPs caused different color formations for 3 metals simultaneously in the sensor study for heavy metal detection, and Fe3+, Cu2+, and Cr6+ ions were detected. The R2 values for H2O2, Fe3+, Cu2+, and Cr6+ were 0.9360, 0.9961, 0.9787, and 0.9625 the limit of detection (LOD) was 43.75, 1.69, 3.18, and 5.05 ppb (ng/mL), respectively. It was determined that Ag@AgCl NPs have the potential to be used as a colorimetric sensor for the detection of H2O2 and heavy metals from wastewater.

Divergent Responses of Hydrophilic CdSe and CdSe@CdS Core-Shell Nanocrystals in Apoptosis and In Vitro Cancer Cell Imaging: A Comparative Analysis

With their distinctive core-shell design, core-shell nanocrystals have drawn interest in catalysis, medicinal research, and nanotechnology. These nanocrystals have a variety of characteristics and possible uses. The application of core-shell nanocrystals offers significant potential in increasing diagnostic and therapeutic approaches for cancer research in apoptosis and in vitro cancer cell imaging. In the present study, we investigated the fluorescence behavior of hydrophilic CdSe (core-only) and CdSe@CdS (core-shell) nanocrystals (NCs) and their potential in cancer cell imaging. The addition of a CdS coating to CdSe NCs increased the fluorescence intensity tenfold. The successful fabrication of core-shell CdSe@CdS nanocrystals was proven by a larger particle size (evaluated via DLS and TEM) and their XRD pattern and surface morphology compared to CdSe (core-only) NCs. When these NCs were used for bioimaging in MCF-7 and HEK-293 cell lines, they demonstrated excellent cellular uptake due to higher fluorescence intensity within cancerous cells than normal cells. Comparative cytotoxicity studies revealed that CdSe NCs were more toxic to all three cell lines (HEK-293, MCF-7, and HeLa) than CdSe@CdS core-shell structures. Furthermore, a decrease in mitochondrial membrane potential and intracellular ROS production supported NCs inducing oxidative stress, which led to apoptosis via the mitochondria-mediated pathway. Increased cytochrome c levels, regulation of pro-apoptotic gene expression (e.g., p53, Bax), and down-regulation of Bcl-2 all suggested cellular apoptosis occurred via the intrinsic pathway. Significantly, at an equivalent dose of core-shell NCs, core-only NCs induced more oxidative stress, resulting in increased apoptosis. These findings shed light on the role of a CdS surface coating in reducing free radical release, decreasing cytotoxicity, and improving fluorescence, advancing the field of cell imaging.

Exposure, toxicological mechanism of endocrine disrupting compounds and future direction of identification using nano-architectonics

Endocrine-disrupting compounds (EDC) are a group of exogenous chemicals that structurally mimic hormones and interfere with the hormonal signaling cascade. EDC interacts with hormone receptors, transcriptional activators, and co-activators, altering the signaling pathway at both genomic and non-genomic levels. Consequently, these compounds are responsible for adverse health ailments such as cancer, reproductive issues, obesity, and cardiovascular and neurological disorders. The persistent nature and increasing incidence of environmental contamination from anthropogenic and industrial effluents have become a global concern, resulting in a movement in both developed and developing countries to identify and estimate the degree of exposure to EDC. The U.S. Environment Protection Agency (EPA) has outlined a series of in vitro and in vivo assays to screen potential endocrine disruptors. However, the multidisciplinary nature and concerns over the widespread application demand alternative and practical techniques for identifying and estimating EDC. The review chronicles the state-of-art 20 years (1990-2023) of scientific literature regarding EDC's exposure and molecular mechanism, highlighting the toxicological effects on the biological system. Alteration in signaling mechanisms by representative endocrine disruptors such as bisphenol A (BPA), diethylstilbestrol (DES), and genistein has been emphasized. We further discuss the currently available assays and techniques for in vitro detection and propose the prominence of designing nano-architectonic-sensor substrates for on-site detection of EDC in the contaminated aqueous environment.