Search Results (224)

Head and neck squamous cell carcinomas (HNSCCs) are the seventh most common form of cancer worldwide, typically characterized by high mortality and significant morbidity, including pain and speech and swallowing disorders. Complete tumor tissue resection, the common first line of therapy, remains a surgical challenge with room for improvements. Because tumor cells express highly specific surface molecules serving as receptors for ligands, specific targeting ligands can be conjugated to fluorescent molecules in order to better visualize tumor borders. Targeted fluorescence-guided surgery (T-FGS) as well as tumor-targeted and near-infrared (NIR) fluorescence imaging are emerging techniques for real-time intraoperative cancer imaging. Targeting agents include nanodots or fluorophores, which have been conjugated to specific ligands like antibodies, peptides, or other synthetic moieties. This article surveys tumor-targeted ligands in recent and current preclinical studies and clinical trials related to HNSCC, highlighting common NIRF dyes used for molecular imaging and their physical properties, working concentrations, and associated risks. Smaller ligands, nanodots, dual-modality NIR dyes, and activatable agents can enhance tumor-targeting processes, resulting in faster, more penetrable, and clearer imaging, which could lead to improved clinical applications and better tumor removal rates in the future. Full article

The Maillard reaction (MR), a non-enzymatic interaction between reducing sugars and amino compounds, plays a pivotal role in developing the flavor, color, and aroma of thermally processed foods. Beyond its culinary relevance, the MR gives rise to a structurally diverse array of compounds, including a novel class of fluorescent nanomaterials known as carbon nanodots (CNDs). These Maillard-derived CNDs, although primarily incidental in food systems, exhibit physicochemical characteristics—such as aqueous solubility, biocompatibility, and tunable fluorescence—that are similar to engineered CNDs currently explored in biomedical fields. While CNDs synthesized through hydrothermal or pyrolytic methods are well-documented for drug delivery and imaging applications, no studies to date have demonstrated the use of Maillard-derived CNDs specifically in drug delivery. This review examines the chemistry of the Maillard reaction, the formation mechanisms and characteristics of food-based CNDs, and their potential functional applications in food safety, bioactivity, and future biomedical use. Additionally, it critically evaluates the health implications of Maillard reaction products (MRPs), including both beneficial antioxidants and harmful by-products such as advanced glycation end-products (AGEs). This integrated perspective highlights the dual role of MR in food quality and human health, while identifying key research gaps needed to harness the full potential of food-origin nanomaterials. Full article

Selenium (Se) is an essential trace element involved in antioxidant redox regulation, thyroid hormone metabolism, and cancer prevention. Among its different forms, elemental selenium (Se⁰), particularly at the nanoscale, has gained growing attention in food, feed, and biomedical applications due to its lower toxicity and higher bioavailability compared to inorganic selenium species. However, the detection of Se⁰ in real samples remains challenging as current analytical methods are time-consuming, labour-intensive, and often unsuitable for rapid analysis. In this study, we developed a method for rapidly measuring Se⁰ using carbon nanodots (CNDs) produced from the Maillard reaction between glucose and glycine. The fabricated CNDs were water-dispersible and strongly fluorescent, with an average particle size of 3.90 ± 1.36 nm. Comprehensive characterisation by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), fluorescence spectroscopy, and Raman spectroscopy confirmed their structural and optical properties. The CNDs were employed as fluorescent probes for the selective detection of Se⁰. The sensor showed a wide linear detection range (0–12.665 mmol L⁻¹), with a low detection limit (LOD) of 0.381 mmol L⁻¹ and a quantification limit (LOQ) of 0.465 mmol L⁻¹. Validation with spiked real samples—including ultra-pure water, tap water, and soft drinks—yielded high recoveries (98.6–108.1%) and low relative standard deviations (<3.4%). These results highlight the potential of CNDs as a simple, reliable, and environmentally friendly sensing platform for trace-level Se⁰ detection in complex food and beverage matrices. Full article

Carbon nanodots have recently attracted attention as fluorescence imaging probes and magnetic resonance imaging (MRI) contrast agents in diagnostic and therapeutic applications due to their unique optical properties. In this work we report the synthesis of biocompatible Mn (II)-doped carbon nanodots and their performance as fluorescence and MRI contrast agents in in vitro assays. The thermal decomposition of a Diphenylhydantoin–Mn(II) complex assured the incorporation of manganese (II) ions in the carbon dots. The obtained materials display a favorable spin density for MRI applications. The synthesized Mn(II)-CNDs also displayed remarkable photoluminescence, with a bright blue emission and good response in in vitro fluorescence imaging. Cytotoxicity investigations revealed good cell viability on malignant melanoma cell lines in a large concentration range. A cytotoxic effect was observed for MG-63 osteosarcoma and breast adenocarcinoma cell lines. The in vitro MRI assays demonstrated the potentialities of the Mn(II)-CNDs as T2 contrast agents at low dosages, with relaxivity values higher than those of commercial ones. Due to the simplicity of their synthetic pathway and their low cytotoxicity, the prepared Mn(II)-CNDs are potential alternatives to currently used contrast agents based on gadolinium complexes. Full article

An electrochemical sensor was developed for the detection of hydrogen peroxide (H₂O₂) based on the in situ formation of a nickel hexacyanoferrate complex on the electrode surface. Screen-printed carbon electrodes were modified with nickel-doped carbon nanodots (Ni-CNDs), and a nickel hexacyanoferrate complex was electrogenerated over the nickel carbon nanodots. Ni-CNDs were synthetized “a la carte” in one step by including nickel (II) acetate as precursor and characterized using different techniques: transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy, atomic force microscopy (AFM), and infrared spectroscopy (FTIR). The electrocatalytic activity toward H₂O₂ reduction and the oxidation of the resulting modified electrodes was studied. The developed sensor had a strong electrocatalytic effect on the oxidation and reduction of H₂O₂, yielding detection limits of 3.22 and 0.49 μM, respectively. The H₂O₂ content of a tap water sample was determined, confirming the viability of the developed electrochemical sensor. Full article

The increasing prevalence of toxic compounds in food, agriculture, and the environment presents a critical challenge to public health and ecological sustainability. Carbon nanodots (CNDs), with their excellent photoluminescence, biocompatibility, and ease of functionalization, have emerged as highly promising materials for developing advanced sensors that target hazardous substances. This review provides a comprehensive overview of the synthesis, functionalization, and sensing mechanisms of CND-based sensors, highlighting their versatile application in detecting toxic compounds such as heavy metals, pesticides, mycotoxins, and emerging contaminants. The article outlines recent advancements in fluorescence, electrochemical, and colorimetric detection strategies and presents key case studies that illustrate the successful application of CNDs in real-world monitoring scenarios. Furthermore, it addresses the challenges associated with reproducibility, scalability, selectivity, and sensor stability and explores future directions for integrating CNDs with smart and sustainable technologies. This review emphasizes the transformative potential of CNDs in achieving rapid, cost-effective, and environmentally friendly toxin detection solutions across multiple domains. Full article

Background: The study aimed to develop a sustainable method for producing myco-nanomaterials, particularly fluorescent carbon nanodots (CNDs), from freeze-dried Pleurotus ostreatus (Agaricomycetes) mushroom powder via pyrolysis. The goal was to investigate how pyrolysis conditions affect CND characteristics and their potential antimicrobial properties. Mushroom powder was pyrolyzed at temperatures ranging from 150 to 240 °C. The resulting products were analyzed for yield, molecular weight, fluorescence intensity, and estimated CND concentration in relation to the carbon-to-nitrogen (C/N) ratio. Antibacterial activity was tested against Escherichia coli and Staphylococcus epidermidis. Product yield decreased from 13.20% at 150 °C to 0.80% at 240 °C. Molecular weight peaked at 200 °C (623.20 kDa), while maximum fluorescence intensity (739.40 A.U.) was observed at 210 °C. A strong positive correlation (R² = 0.72) was found between the C/N ratio and estimated CND concentration. Antimicrobial testing revealed notable inhibition of E. coli, associated with higher fluorescence intensity and CND content. Pyrolyzed P. ostreatus mushroom powder offers a promising, eco-friendly platform for producing luminescent, carbonaceous nanomaterials with antibacterial potential. These non-purified, myco-derived nanomaterials may contribute to green nanotechnology development and antimicrobial strategies. Full article

Background: The design of multifunctional carbon based nanosystems exhibiting light-triggered hyperthermia, emission, low cytotoxicity, and drug delivery capability is of significant interest in the area of nanomaterials. In this study, we present red-emitting and photothermal carbon nanodots (Cdots-βCD/PTC) obtained by the encapsulation of hydrophobic pentacene (PTC) within Carbon nanodots (Cdots) synthesized from beta-cyclodextrin (βCD). Methods: The prepared nanostructures were investigated in terms of morphology, size, and optical properties, by absorption and emission optical spectroscopy, atomic force microscopy, dynamics light scattering, Z-potential, nuclear magnetic resonance, and infra-red spectroscopy. Molecular modelling simulation was used to investigate the geometry and the stabilization energy of the Cdots-βCD/PTC inclusion complex. Results: The as prepared Cdots-βCD/PTC demonstrated good water dispersibility, green-emission (ϕ_PL = 1.7%), and photothermal conversion (η = 17.4%) upon red-light excitation (680 nm). Furthermore, Cdots-βCD/PTC low cytotoxicity in the range 0.008 μg–0.8 μg and good interaction with albumin protein (K_SV = 2.78 ± 0.28 mL mg⁻¹) were demonstrated. Molecular simulation analysis revealed the formation of the inclusion complex with an energy of −5.32 kcal mol⁻¹, where PTC is orthogonally oriented in the βCD cavity. Conclusions: The results presented in this work highlight the potential of Cdots-βCD/PTC as a novel versatile nanosystem for biomedical applications, such as bioimaging and site-specific photothermal treatment of cancer cells. Full article

Spices contain abundant essential oils and active compounds, which can be difficult to introduce into living cells due to their apolar, lipophilic nature. Carbon nanoparticles, produced through the Maillard reaction during food heat treatment, are small enough to enter cells easily. This study explores how thermal processing affects the formation of carbon nanodots (CNDs) in spices, revealing that higher temperatures boost CND synthesis, thus enhancing bioavailability and biological effectiveness. Interestingly, turmeric and black pepper enriched with CNDs notably influenced yeast fermentation, with an overall increase in antioxidant capacity, especially in turmeric and chili pepper. However, excessive heat occasionally reduced antioxidant activity, suggesting the breakdown of sensitive compounds. These findings highlight the potential of CND-enriched spices for health and nutrition applications. Full article

Metal-doped carbon dots (CDs) have become one of the most popular catalytic materials for Fenton-like reactions, mainly due to their low production cost, minimal toxicity, and high catalytic efficiency. Theses reactions not only provide an efficient decontamination method for the degradation of organic pollutants in wastewater but also demonstrate a wide range of sensing applications. Metal doping introduces new catalytically active centres, which increase the binding selectivity to the reactants and offer an additional advantage of improved catalytic degradation and sensing activity. The metal-doped CDs optimise the electronic structure of pristine CDs, thereby enhancing their catalytic properties and reaction rates. These enhancements make them an attractive option for water treatment and sensor design. The objective of this review is to provide a comprehensive overview of the current research progress in the utilisation of metal-doped CDs as Fenton-like reaction catalysts for the degradation of pollutants and sensing applications. This review examines the advantages of metal-doped carbon dots in terms of catalytic efficiency, selectivity, and application scope and discusses the potential challenges and future research directions. The aim is to promote further the sustainable application and green development of CD technology in environmental governance and analytical chemistry. Full article

The increasing demand for innovative, sustainable, and functional food packaging solutions has led to the exploration of polyaniline (PANI) and carbon nanodots (CNDs) as promising materials for smart packaging. This study investigates the potential of PANI/CND composites for electrochemical sensing of alcohols, a key indicator of spoilage in food products. By leveraging the unique properties of PANI, a conducting polymer, and the fluorescence and electrochemical activity of CNDs, we propose a dual-function smart packaging material capable of real-time monitoring of alcohol levels, which are often released during the fermentation or degradation of food. The integration of PANI with CNDs enhances the material’s sensitivity and stability, offering a cost-effective, environmentally friendly, and responsive solution for freshness and spoilage detection. The electrochemical sensing mechanism allows for rapid, non-destructive testing, providing consumers and food producers with an efficient tool to assess product quality and safety. This work paves the way for the development of intelligent packaging systems that can not only detect spoilage but also actively contribute to food preservation, reducing waste and improving food safety. Full article

Carbon Nanodots (CNDs) are characterized by their nanoscale size (<10 nm), biocompatibility, stability, fluorescence, and photoluminescence, making them a promising candidate for cancer therapy. The difference in the methods of synthesis of CNDs, whether top-down or bottom-up, affects the formation, visual, and surface characteristics of CNDs, which are crucial for their biomedical and pharmaceutical applications. The urgent need for innovative therapeutic strategies from CNDs is due to the limitations and barriers posed by conventional therapies including drug resistance and cytotoxicity. Nano-loaded chemotherapy treatments are highly effective and can enhance the solubility and targeted delivery of chemotherapeutic agents, generate reactive oxygen species (ROS) to induce cancer cell cytotoxicity, and regulate intracellular signaling pathways. Their ability to be designed for cellular uptake and exact intracellular localization further improves their therapeutic potential. In addition to working on drug delivery, CNDs are highlighted for their dual functionality in imaging and therapy, which allows real-time observing of treatment efficacy. Despite the development of these treatments and the promising results for the future, challenges still exist in cancer treatment. Full article

Synthetic non-metallic nanoparticles (NMNPs) such as carbon nanotubes (CNTs), carbon nanodots (CNDs), and cell-penetrating peptides (CPPs) have been explored to treat harmful algal blooms. However, their strain-specific algicidal activities have been rarely investigated. Here we determined their acute toxicity to nine freshwater cyanobacterial strains belonging to seven genera, including Microcystis aeruginosa UTEX 2386, M. aeruginosa UTEX 2385, M. aeruginosa LE3, Anabaena cylindrica PCC 7122, Aphanizomenon sp. NZ, Planktothrix agardhii SB 1810, Synechocystis sp. PCC 6803, Lyngbya sp. CCAP 1446/10, and Microcoleus autumnale CAWBG635 ATX. We prepared in-house three batches of CNDs using glucose (CND-G) or chloroform and methanol (CND-C/M) as the substrate and one batch of single-walled CNTs (SWCNTs). We also ordered a commercially synthesized CPP called γ-Zein-CADY. The axenic laboratory culture of each cyanobacterial strain was exposed to an NMNP at two dosage levels (high and low, with high = 2 × low) for 48 h, followed by measurement of five endpoints. The endpoints were optical density (OD) at 680 nm (OD₆₈₀) for chlorophyll-a estimation, OD at 750 nm (OD₇₅₀) for cell density, instantaneous pigment fluorescence emission (FE) after being excited with 450 nm blue light (FE₄₅₀) for chlorophyll-a or 620 nm red light (FE₆₂₀) for phycocyanin, and quantum yield (QY) for photosynthesis efficiency of photosystem II. The results indicate that the acute toxicity was strain-, NMNP type-, dosage-, and endpoint-dependent. The two benthic strains Microcoleus autumnale and Lyngbya sp. were more resistant to NMNP treatment than the other seven free-floating strains. SWCNTs and fraction A14 of CND-G were more toxic than CND-G and CND-C/M. The CPP was the least toxic. The high dose generally caused more severe impairment than the low dose. OD₇₅₀ and OD₆₈₀ were more sensitive than FE₄₅₀ and FE₆₂₀. QY was the least sensitive endpoint. The strain dependence of toxicity suggested the potential application of these NMNPs as a target-specific tool for mitigating harmful cyanobacterial blooms. Full article

We are committed to writing this narrative review given that carbon-based nanomaterials are revolutionizing dental medicine. Since the groundbreaking discovery of carbon nanotubes in 1991, their dental applications have skyrocketed. The numbers speak for themselves: in 2024, the global carbon nanotubes market hit USD 1.3 billion and is set to double to USD 2.6 billion by 2029. Over the past few decades, various forms of carbon nanomaterials have been integrated into dental practices, elevating the quality and effectiveness of dental treatments. They represent a transformative advancement in dentistry, offering numerous benefits such as augmented mechanical properties, antimicrobial activity, and potential for regenerative applications. Both carbon nanotubes (CNTs) and carbon dots (CDs) are derived from carbon and integral to nanotechnology, showcasing the versatility of carbon nanostructures and delivering cutting-edge solutions across diverse domains, such as electronics, materials science, and biomedicine. CNTs are ambitiously examined for their capability to reinforce dental materials, develop biosensors for detecting oral diseases, and even deliver therapeutic agents directly to affected tissues. This review synthesizes their current applications, underscores their interdisciplinary value in bridging nanotechnology and dentistry, identifies key barriers to clinical adoption, and discusses hybrid strategies warranting further research to advance implementation. Full article

Developing a catalyst with excellent electrical conductivity and catalytic performance for on-site testing of residual imidacloprid is significant and challenging. In situ growth of Mo₂C nanodots on Co-induced N-doped carbon nanotubes (Co/Mo₂C/N-CNT) was synthesized to construct a molecularly imprinted electrochemical sensor for the detection of imidacloprid. The results proved that the catalytic performance of Co/Mo₂C/N-CNT for imidacloprid was over two times higher than those of Co/N-CNT and commercial CNT. This improvement was attributed to the formation of a heterostructure between Co species, Mo₂C, and N-CNT, which facilitated highly exposed catalytic active sites. Additionally, the abundant Mo₂C nano-dots promoted interfacial charge transfer to achieve optimal dynamics. The optimum preparation parameters of the catalysts were obtained by response surface methodology. By analyzing the relationship between different pH values and peak potential, as well as the influence of different scanning rates on peak potential, it was deduced that the possible electrocatalytic mechanism of imidacloprid involved the reduction of the nitro group to a hydroxylamine group and H₂O. Under optimal conditions, the limit of detection (LOD) was 0.033 × 10⁻⁶ mol·L⁻¹ (R² = 0.99698), and the linear range was 0.1 × 10⁻⁶~100 × 10⁻⁶ mol·L⁻¹. The application effect of the prepared sensor was evaluated by measuring the imidacloprid in two kinds of tea, indicating that the sensor possessed good sensitivity and selectivity, and was capable of meeting the requirements of on-site detection. Full article