Brewery spent grain derived carbon dots for metal sensing

Abstract

This article presents a proof-of-concept to recycle microbrewery waste as a carbon source for synthesizing carbon dots (CDs).

Revealing the synergetic interaction between amino and carbonyl functional groups and their effect on the electronic and optical properties of carbon dots

“…[16][17][18][19][20] For example, as is well known, the absorption peaks of CDs are mainly in the UV and visible light regions. [21][22][23] Then, our groups utilized a large amount of nitrogen source to broaden the CDs' absorption from UV-Vis to the first NIR window region (650-900 nm), which opened a new potential application as a photothermal agent in photothermal therapy. 24,25 Experimentally, the first NIR absorption window was probably attributed to the nitrogen functional groups.…”

Microwave synthesized novel biomass carbon dots applied in the fluorescent detection of crystal violet

“…Peaks at 532.0 and 532.8 eV were observed in the high‐resolution XPS spectrum of O 1s in Figure 3c, which were the peaks of C‐O‐C/C‐OH and C=O, respectively [37]. Peaks at 399.2 and 400.2 eV in the high‐resolution XPS spectrum of N 1s (Figure 3d) were attributed to pyrrolic N and N‐H, respectively, illustrating that the as‐prepared CDs possessed pyrrole derived from the chlorophyll of water spinach [38]. Above all, the fabricated CDs superficially contained a large number of carboxyl, hydroxyl, and pyrrole groups verifying the successful eco‐friendly synthesis of water‐soluble CDs by the microwave method.…”

“…The main peak at286.3 eV attributed to C 1s was divided into three contributing peaks at 284.8, 285.7, and 286.4 eV (Figure 3b), which indicated the presence of three carbon environments of C-C/C=C, C-O-C/C-OH, and C-N, respectively, illustrating the presence of a large number of hydrophilic groups on the surface of CDs, among which the existence of C-C bonds revealed the formation of the sp 2 domain or graphite nucleus of CDs[35,36]. Peaks at 532.0 and 532.8 eV were observed in the high-resolution XPS spectrum of O 1s in Figure3c, which were the peaks of C-O-C/C-OH and C=O, respectively[37].Peaks at 399.2 and 400.2 eV in the high-resolution XPS spectrum of N 1s (Figure3d) were attributed to pyrrolic N and N-H, respectively, illustrating that the as-prepared CDs possessed pyrrole derived from the chlorophyll of water spinach[38]. Above all, the fabricated CDs superficially contained a large number of carboxyl, hydroxyl, and pyrrole groups verifying the successful eco-friendly synthesis of watersoluble CDs by the microwave method.…”

Plant-based carbon dots are a sustainable alternative to conventional nanomaterials for biomedical and sensing applications

“…Microwave irradiation facilitates solvent-free water-mediated reactions and controlled heating. Ankita Deb et al (2022) [62]. They conducted a carbonization pretreatment of brewery spent grain, wherein they dissolved 5 g of the material in 10 ml of water and exposed it to microwave irradiation at various temperatures and durations, ranging from 200 °C to 300 °C for 10 to 30 min.…”