Preparation of Multifunctional N-Doped Carbon Quantum Dots from Citrus clementina Peel: Investigating Targeted Pharmacological Activities and the Potential Application for Fe3+ Sensing

Abstract

Carbon quantum dots (CQDs) have recently emerged as innovative theranostic nanomaterials, enabling fast and effective diagnosis and treatment. In this study, a facile hydrothermal approach for N-doped biomass-derived CQDs preparation from Citrus clementina peel and amino acids glycine (Gly) and arginine (Arg) has been presented. The gradual increase in the N-dopant (amino acids) nitrogen content increased the quantum yield of synthesized CQDs. The prepared CQDs exhibited good biocompatibility, stability in aqueous, and high ionic strength media, similar optical properties, while differences were observed regarding the structural and chemical diversity, and biological and antioxidant activity. The antiproliferative effect of CQD@Gly against pancreatic cancer cell lines (CFPAC-1) was observed. At the same time, CQD@Arg has demonstrated the highest quantum yield and antioxidant activity by DPPH scavenging radical method of 81.39 ± 0.39% and has been further used for the ion sensing and cellular imaging of cancer cells. The obtained results have demonstrated selective response toward Fe3+ detection, with linear response ranging from 7.0 µmol dm−3 to 50.0 µmol dm−3 with R2 = 0.9931 and limit of detection (LOD) of 4.57 ± 0.27 µmol dm−3. This research could be a good example of sustainable biomass waste utilization with potential for biomedical analysis and ion sensing applications.

N-Doped Carbon Quantum Dots for Differential Detection of Doxycycline in Pharmaceutical Sewage and in Bacterial Cell

“…19 As CQDs have a low quantum yield (QY), 20 additional treatments such as organic molecule surface stabilization, doping with heteroatoms like sulfur and nitrogen, and size control are frequently required to improve the QY. 21 The most popular method of enhancing CQD performance is to use nitrogen doping. 21 Herein, we synthesized a simple ecofriendly fluorescent probe based on nitrogen doped carbon quantum dots (N-CQDs) for selective and differential detection of DC.…”

“…21 The most popular method of enhancing CQD performance is to use nitrogen doping. 21 Herein, we synthesized a simple ecofriendly fluorescent probe based on nitrogen doped carbon quantum dots (N-CQDs) for selective and differential detection of DC. The bright blue fluorescence quantum dots were synthesized via a simple microwave-assisted method using ascorbic acid and diethylenetriamine (DETA) as carbon and nitrogen sources, respectively.…”

“…They have been widely used as fluorescent labels for decades. − CQDs outperform the inorganic semiconductor QDs in terms of water solubility, biocompatibility, and ease of use, making them ideal for applications, especially in biosensing, bioimaging, and environmental monitoring. − Recently, fluorescent CQDs have been prepared via electrochemical exfoliation, laser ablation, and oxidative acid treatment of carbon materials, as well as microwave irradiation, pyrolysis, ultrasonic treatment, and hydrothermal treatment of a variety of organic precursors . As CQDs have a low quantum yield (QY), additional treatments such as organic molecule surface stabilization, doping with heteroatoms like sulfur and nitrogen, and size control are frequently required to improve the QY . The most popular method of enhancing CQD performance is to use nitrogen doping .…”

In Vivo Imaging Evaluation of Fluorescence Intensity at Tail Emission of Near-Infrared-I (NIR-I) Fluorophores in a Porcine Model

“…As for fluorophores, NIR-II nanomaterials have recently been developed (single-walled carbon nanotubes, quantum dots, and rare-earth-doped nanoparticles). For instance, Safranko et al demonstrated high quantum yield and antioxidant activity in a sustainable biomass waste model that enabled ion sensing and cellular imaging of cancer cells [ 20 ].…”

Development of Intraoperative Near-Infrared Fluorescence Imaging System Using a Dual-CMOS Single Camera

“…The clinical application of NIR fluorescence imaging systems is expanding based on real-time imaging of biological tissues using fluorescence contrast agents. Furthermore, the development of new types of fluorophores for specific cancer diagnosis and treatment has increased the potential of these imaging systems [ 24 , 25 , 26 ].…”