Green synthesis of multifunctional carbon dots for anti-cancer and anti-fungal applications

Carbon dots: Types, preparation, and their boosted antibacterial activity by photoactivation. Current status and future perspectives

Carbon dots (CDs) correspond to carbon-based materials (CBM) with sizes usually below 10 nm. These nanomaterials exhibit attractive properties such us low toxicity, good stability, and high conductivity, which have promoted their thorough study over the past two decades. The current review describes four types of CDs: carbon quantum dots (CQDs), graphene quantum dots (GQDs), carbon nanodots (CNDs), and carbonized polymers dots (CPDs), together with the state of the art of the main routes for their preparation, either by "top-down" or "bottom-up" approaches. Moreover, among the various usages of CDs within biomedicine, we have focused on their application as a novel class of broad-spectrum antibacterial agents, concretely, owing their photoactivation capability that triggers an enhanced antibacterial property. Our work presents the recent advances in this field addressing CDs, their composites and hybrids, applied as photosensitizers (PS), and photothermal agents (PA) within antibacterial strategies such as photodynamic therapy (PDT), photothermal therapy (PTT), and synchronic PDT/PTT. Furthermore, we discuss the prospects for the possible future development of large-scale preparation of CDs, and the potential for these nanomaterials to be employed in applications to combat other pathogens harmful to human health. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

Quantum Dots and Their Interaction with Biological Systems

Quantum dots are nanocrystals with bright and tunable fluorescence. Due to their unique property, quantum dots are sought after for their potential in several applications in biomedical sciences as well as industrial use. However, concerns regarding QDs’ toxicity toward the environment and other biological systems have been rising rapidly in the past decade. In this mini-review, we summarize the most up-to-date details regarding quantum dots’ impacts, as well as QDs’ interaction with mammalian organisms, fungal organisms, and plants at the cellular, tissue, and organismal level. We also provide details about QDs’ cellular uptake and trafficking, and QDs’ general interactions with biological structures. In this mini-review, we aim to provide a better understanding of our current standing in the research of quantum dots, point out some knowledge gaps in the field, and provide hints for potential future research.

A Strategic Review on Carbon Quantum Dots for Cancer-Diagnostics and Treatment

The understanding of the genesis of life-threatening cancer and its invasion calls for urgent development of novel technologies for real-time observations, early diagnosis, and treatment. Quantum dots (QDs) grabbed the spotlight in oncology owing to their excellent photostability, bright fluorescence, high biocompatibility, good electrical and chemical stability with minimum invasiveness. Recently, carbon QDs (CQDs) have become popular over toxic inorganic QDs in the area of bioimaging, biosensing, and drug delivery. Further, CQDs derived from natural sources like biomolecules and medicinal plants have drawn attention because of their one-pot, low-cost and ease of synthesis, along with remarkable tunable optical properties and biocompatibility. This review introduces the synthesis and properties of CQDs derived from natural sources, focusing on the applicability of CQD-based technologies as nano-theranostics for the diagnosis and treatment of cancer. Furthermore, the current issues and future directions for the transformation of CQDs-based nanotechnologies to clinical applications are highlighted.

Green synthesis of multifunctional carbon quantum dots: An approach in cancer theranostics

Carbon quantum dots (CQDs) have gained significant growing attention in the recent past due to their peculiar characteristics including smaller size, high surface area, photoluminescence, chemical stability, facile synthesis and functionalization possibilities. They are carbon nanostructures having less than 10 nm size with fluorescent properties. In recent years, the scientific community is curiously adopting biomass precursors for the preparation of CQDs over the chemical compounds. These biomass sources are sustainable, eco-friendly, inexpensive, widely available and convert waste into valuable materials. Hence in our work the fundamental understating of diverse fabrication methodologies of CQDs, and the types of raw materials employed in recent times, are all examined and correlated comprehensively. Their unique combination of remarkable properties, together with the ease with which they can be fabricated, makes CQDs as promising materials for applications in diverse biomedical fields, in particular for bio-imaging, targeted drug delivery and phototherapy for cancer treatment. The mechanism for luminescence is of considerable significance for leading the synthesis of CQDs with tunable fluorescence emission. Therefore, it is aimed to explore and provide an updated review on (i) the recent progress on the different synthesis methods of biomass-derived CQDs, (ii) the contribution of surface states or functional groups on the luminescence origin and (iii) its potential application for cancer theranostics, concentrating on their fluorescence properties. Finally, we explored the challenges in modification for the synthesis of CQDs from biomass derivatives and the future scope of CQDs in phototherapy for cancer theranostics.