Although carbon nanoparticles or quantum dots (C-dots) have been studied extensively for a variety of applications (e.g., photocatalysis, metal ion sensing, antibacterial, cell labeling), a greener synthetic method is highly indispensable. Herein, we report a facile one-step hydrothermal carbonization approach for the synthesis of fluorescent blue/green C-dots using oyster mushroom (Pleurotus species). First, we demonstrate the application of these C-dots as a colorimetric sensor for toxic metal ions detection such as heavy metal Pb2+ ions with the limit of detection (LOD) and limit of quantification (LOQ) of 58.63 μM and 177.69 μM, respectively. Second, we show the application of C-dots as a promising fluorescent probe for DNA recognition through the electrostatic intercalative interaction between ctDNA and C-dots. Third, we demonstrate the efficient antibacterial activity of C-dots against three bacterial strains (Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa). Finally, the anticancer activity of C-dots against MDA-MB-231 breast cancer cells is demonstrated.

Generally, silver is considered as a noble metal used for treating burn wound infections, open wounds and cuts. However, the emerging nanotechnology has made a remarkable impact by converting metallic silver into silver nanoparticles (AgNPs) for better applications. The advancement in technology has improved the synthesis of NPs using biological method instead of physical and chemical methods. Nonetheless, synthesizing AgNPs using biological sources is ecofriendly and cost effective. Till date, AgNPs are widely used as antibacterial agents; therefore, a novel idea is needed for the successful use of AgNPs as therapeutic agents to uncertain diseases and infections. In biomedicine, AgNPs possess significant advantages due to their physical and chemical versatility. Indeed, the toxicity concerns regarding AgNPs have created the need for non-toxic and ecofriendly approaches to produce AgNPs. The applications of AgNPs in nanogels, nanosolutions, silver based dressings and coating over medical devices are under progress. Still, an improvised version of AgNPs for extended applications in an ecofriendly manner is the need of the hour. Therefore, the present review emphasizes the synthesis methods, modes of action under dissipative conditions and the various biomedical applications of AgNPs in detail.

No abstract

Approximately every 100 years, as witnessed in the last two centuries, we are facing an influenza pandemic, necessitating the need to combat a novel virus strain. As a result of the new coronavirus (severe acute respiratory syndrome coronavirus type 2 [SARS‐CoV‐2] outbreak in January 2020, many clinical studies are being carried out with the aim of combating or eradicating the disease altogether. However, so far, developing coronavirus disease 2019 (COVID‐19) detection kits or vaccines has remained elusive. In this regard, the development of antiviral nanomaterials by surface engineering with enhanced specificity might prove valuable to combat this novel virus. Quantum dots (QDs) are multifaceted agents with the ability to fight against/inhibit the activity of COVID‐19 virus. This article exclusively discusses the potential role of QDs as biosensors and antiviral agents for attenuation of viral infection.

No abstract

No abstract

To develop surfactant based metallodrugs, it is important to know the role of the tail part of the surfactant-metal complexes in their hydrophobicity, micellization behaviour, interaction with biomacromolecules and cell penetration. Here, we have taken a new series of single and double chain surfactant-cobalt(III) complexes with alkylamine ligands of different chain length, [Co(dien)(DA)Cl 2 ]ClO 4 (1), [Co(dien)(HA)-Cl 2 ]ClO 4 (2), [Co(dien)(DA) 2 Cl](ClO 4 ) 2 (3) and [Co(dien)(HA) 2 Cl](ClO4) 2 (4), where dien = diethylenetriamine, DA = dodecylamine and HA = hexadecylamine. The complexes were characterised by elemental analysis, NMR, ESI-MS, UV-visible and FTIR techniques. In addition, the average size distribution and morphology of self-assembled surfactant-cobalt(III) complexes were examined by DLS and SEM, respectively.The hydrophobicity, critical micelle concentration (CMC) values, thermodynamics of micellization (ΔG°m, ΔH°m and ΔS°m) and the nature of the interaction of these complexes with bovine and human serum albumins (BSA/HSA) were evaluated. The obtained CMC values were in the order 1 > 2 > 3 > 4, indicating that double chain systems have lower CMC values compared to single chain systems due to the increase in the hydrophobicity of the alkyl amine ligands. The thermodynamics of micellization indicated that the process is spontaneous, exothermic and entropy driven. The interaction of complexes 1-4 with serum albumins indicated that the quenching process follows a static mechanism, and the extent of quenching and binding parameters were in the order 1 < 2 < 3 < 4. Interestingly, on increasing the temperature, the protein-complex stability decreased for the single chain systems, and increased for the double chain systems, probably due to the involvement of electrostatic and hydrophobic interactions. This was further supported by the thermodynamics of protein interaction and synchronous fluorescence studies. Moreover, the results from UV-vis, synchronous and circular dichroism (CD) showed the occurrence of conformational and micro environmental changes in BSA/HSA. It is also noted that BSA has more binding affinity with surfactant-metal complexes compared to HSA. Furthermore, the antimicrobial effects of these complexes were investigated by disk diffusion method; complex 4 has a better antimicrobial activity due to the ease of bacterial cell penetration due to its more hydrophobic nature.

No abstract