Prosopis juliflora hydrothermal synthesis of high fluorescent carbon dots and its antibacterial and bioimaging applications

Carbon dots decorated cadmium sulfide nanomaterials for boosting photocatalytic activity for ciprofloxacin degradation

This study investigates the utilization of carbon dots (CDs) from neem leaves (Azadirachta indica) decorated onto cadmium sulfide (CdS) for the photocatalytic degradation of ciprofloxacin. A comparative study of ciprofloxacin degradation with pristine CdS and CD decorated CdS demonstrated high degradation of ∼ 75 % with CD/CdS when compared to bare CdS (∼68 %). Process optimization studies were further carried out with CD/CdS catalysts at different solution pH (4-10), feed concentrations (10-50 mg/L), catalyst loadings (25-125 mg/L), temperatures (10 - 30 °C), and lamp power (25, 50, 250 W and sunlight). Higher temperatures, combined with a solution pH of 7 and catalyst loading of 100 mg/L favored the enhanced degradation of 20 mg/L of ciprofloxacin. The ciprofloxacin degradation rate increased linearly with temperature with an apparent activation energy of 27 kJ mol-1. The CD/CdS photocatalyst demonstrated maximum degradation rates with higher lamp powers while it also showed remarkable performance under natural sunlight achieving the same degradation within 3 h.

Heteroatom-doped carbon dots from medicinal plants as novel biomaterials for as-use biomedical applications in comparison with synthetic drug, zaltoprofen

FN-doped carbon dots were synthesized using powdered leaves of Moringa oleifera L./Chromolaena odorata L./Tridax procumbens L./Tinospora cordifolia L./ and Lantana camara L., along with a precursor called 4,5-difluoro-1,2-benzenediamine (DFBD) and compared against the drug zaltoprofen derived carbon dots. They were assessed for their optical and structural characteristics using photoluminescence (optimal emission λ of 600 nm), vibrational (FTIR) spectroscopy (characteristic wave numbers of 1156 and 1269 cm-1 for C-F), as well as X-ray diffraction (XRD) (highest intensity at 27.56°) and high-resolution transmission electron microscopy (HR-TEM) (particles in the size range of 15-20 nm). Further, field emission scanning electron microscopy (FESEM) / energy dispersive spectroscopy (EDX) indicated FN doping of oval/oblong carbon dots. Membrane protection in percent is found to be 55.3 and 80.4 for FN-CDs and Z-FN-CDs respectively. The DPPH-free radical scavenging activity by FN-CDs was 69.4%, while with Z-FN-CDs, it was 54.2%. When tested on six bacterial strains (three each for gram-positive and gram-negative), the FN-CDs displayed a halo (ZOI) between 9 and 19 mm, whereas the Z-FN-CDs displayed a clearance zone between 9 and 17 mm. The FN-CDs showed significant emission-red-shift effects and demonstrated concentration-dependent biocompatibility and viability in neuroblastoma and beta-TC6-cell lines.

Recent Advances of carbon Pathways for Sustainable Environment development

Carbon dots (CDs) are an emerging type of carbon nanomaterial with strong biocompatibility, distinct chemical and physical properties, and low toxicity. CDs may emit fluorescence in the ultraviolet (UV) to near-infrared (NIR) range, which renders them beneficial for biomedical applications. CDs are usually made from carbon precursors and can be synthesized using top-down and bottom-up methods and it can be easily functionalized using different methods. For specific cases of biomedical applications carbon dot functionalization augments the materials' characteristics. Novel functionalization techniques are still being investigated. This review will look at the benefits of functionalization to attain a high yield and various biological applications. Biomedical applications such as photodynamic and photothermal therapy, biosensing, bioimaging, and antiviral and antibacterial properties will be covered in this review. The future applications of green synthesized carbon dots will be determined in part by this review.

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.

A recent update on development, synthesis methods, properties and application of natural products derived carbon dots

Natural resources are practically infinitely abundant in nature, which stimulates scientists to create new materials with inventive uses and minimal environmental impact. Due to the various benefits of natural carbon dots (NCDs) from them has received a lot of attention recently. Natural products-derived carbon dots have recently emerged as a highly promising class of nanomaterials, showcasing exceptional properties and eco-friendly nature, which make them appealing for diverse applications in various fields such as biomedical, environmental sensing and monitoring, energy storage and conversion, optoelectronics and photonics, agriculture, quantum computing, nanomedicine and cancer therapy. Characterization techniques such as Photoinduced electron transfer, Aggregation-Induced-Emission (AIE), Absorbance, Fluorescence in UV-Vis and NIR Regions play crucial roles in understanding the structural and optical properties of Carbon dots (CDs). The exceptional photoluminescence properties exhibited by CDs derived from natural products have paved the way for applications in tissue engineering, cancer treatment, bioimaging, sensing, drug delivery, photocatalysis, and promising remarkable advancements in these fields. In this review, we summarized the various synthesis methods, physical and optical properties, applications, challenges, future prospects of natural products-derived carbon dots etc. In this expanding sector, the difficulties and prospects for NCD-based materials research will also be explored.

Plant Extract-Derived Carbon Dots as Cosmetic Ingredients

Plant extract-derived carbon dots (C-dots) have emerged as promising components for sustainability and natural inspiration to meet consumer demands. This review comprehensively explores the potential applications of C-dots derived from plant extracts in cosmetics. This paper discusses the synthesis methodologies for the generation of C-dots from plant precursors, including pyrolysis carbonization, chemical oxidation, hydrothermal, microwave-assisted, and ultrasonic methods. Plant extract-derived C-dots offer distinct advantages over conventional synthetic materials by taking advantage of the inherent properties of plants, such as antioxidant, anti-inflammatory, and UV protective properties. These outstanding properties are critical for novel cosmetic applications such as for controlling skin aging, the treatment of inflammatory skin conditions, and sunscreen. In conclusion, plant extract-derived C-dots combine cutting-edge nanotechnology and sustainable cosmetic innovation, presenting an opportunity to revolutionize the industry by offering enhanced properties while embracing eco-friendly practices.