One-step Synthesis of Biomass-Based Carbon Dots for Detection of Metal Ions and Cell Imaging

Abstract

Biomass-based carbon dots (Bio-CDs) were prepared from dehydroabietic acid using a one-step hydrothermal process. Characterization by TEM, XPS and FTIR spectroscopy showed that the Bio-CDs are spherical nanoparticles containing mainly C, N and O elements, with functional groups such as amino and carbonyl groups on their surface. The optical properties of the Bio-CDs were studied in detail. A solution of Bio-CDs exhibited excitation-dependent blue fluorescence emission. The solution showed excellent photostability under ultraviolet light and the fluorescence intensity could be enhanced by decreasing the temperature. The intensity of fluorescence emission of the solution was essentially unchanged over the pH range 3.91–8.69, and in the presence of different anions and cations, other than Fe3+ and Pb2+. Fe3+ and Pb2+ ions, respectively, quenched and enhanced the intensity of the fluorescence emission of the solution, allowing sensitive and selective detection of Fe3+ (LOD = 2.33 μM, Em = 437 nm) and of Pb2+ (LOD = 0.27 μM, Em = 437 nm and LOD = 0.33 μM, Em = 500 nm). As a further demonstration of potential applications, the Bio-CDs were shown to have low cytotoxicity and to stain cell nuclei as effectively as the commonly used nuclear stain 4′,6-diamino-2-phenylindole (DAPI), demonstrating their promise in the field of cell imaging.

Recent Advances on Biological Activities and Structural Modifications of Dehydroabietic Acid

“…Recently, Xin et al reported that novel multifunctional nanomedicines assembled from chitosan oligosaccharide-melanin complexes and dehydroabietic acid hexamers can achieve efficient and precise treatment of tumors [24]. Huang et al found that biomass-based carbon dots prepared from dehydroabietic acid by hydrothermal reaction not only can sensitively and selectively detect heavy metal ions, but also can be used for cell imaging with low cytotoxicity [25]. However, while its biological activities were diverse, it had certain toxic and side effects.…”

High-Efficiency Utilization of Waste Tobacco Stems to Synthesize Novel Biomass-Based Carbon Dots for Precise Detection of Tetracycline Antibiotic Residues

“…Driven by this motivation, a variety of biomass-derived nanomaterials have emerged and are widely used in biological/chemical sensing [2][3][4][5][6][7]. Among them, biomass-based carbon dots (C−dots), a promising fluorescent carbon-based nanomaterial, have been widely developed for applications such as environmental pollution traceability analysis, food safety assessment, bioimaging, fluorescent ink, photocatalysis, etc., owing to their unique optical properties, low cost, water solubility, high stability, biocompatibility, and eco-friendliness [8][9][10]. Until now, the reported biobased C−dots have been primarily derived from the biomass-related precursors of tree leaves [11,12], corn stalk shells [13,14], peanut shells [15], coffee [16], capsicum [17], and watermelon peel through various thermal synthesis techniques [18], but little attention has been focused on employing waste tobacco stems as a biomass−related precursor to synthesize efficient and green biomass-based C−dots.…”