A copper-based nanoenzyme (Cu-BL) co-modified by L-L-lysine and 2-2-amino terephthalic acid has laccase-like activity and fluorescence characteristics. Based on this, a colorimetric and fluorescent dual-mode sensor was developed to visually and quantitatively detect tetracycline antibiotics (TCs), including tetracycline (TC), chlortetracycline (CTC), and oxytetracycline (OTC). In the colorimetric detection system, TCs can inhibit the generation of singlet oxygen (¹O₂) and weaken the ability of 2,4-dichlorophenol (2,4-DP) to be oxidized into pink-colored quinone substances. The linear ranges are 0.5–80 μM, 1–80 μM, and 0.25–80 μM, and the detection limits are 0.27 μM, 0.22 μM, and 0.26μM, respectively. In addition, due to the inner filter effect, tetracycline antibiotics can interact with Cu-BL, and with the increase in tetracycline antibiotic concentration, the fluorescence intensity will decrease. In addition, the smartphone sensing platform is combined with the colorimetric signal for the rapid and visual quantitative detection of tetracycline antibiotics. Generally speaking, the colorimetric/fluorescence dual-mode sensor demonstrates good stability, high specificity, and strong anti-interference capabilities, highlighting its practical application potential. This work is expected to offer novel insights for the development of multifunctional nanoenzymes and the integration of a multi-mode sensing platform.

This review focuses on the research progress related to carbon dots (CDs) derived from Chinese herbal medicines and tea, covering preparation methods, physicochemical properties, and application fields. It elaborates on preparation approaches like hydrothermal, solvothermal, microwave-assisted, and ultrasonic-assisted methods, and their influence on CDs’ structure and properties. It also explores CDs’ structural and optical properties. The application fields include antibacterial, sensing, bioimaging, photocatalysis, hemostasis, and energy. Carbon dots show antibacterial activity by destroying bacterial cell membranes, they can detect various substances in sensing, are important for bioimaging, degrade organic pollutants in photocatalysis, have hemostatic and anti-inflammatory effects, and can be used as battery anode materials. Despite progress, challenges remain in improving yield, quantum yield, property control, and understanding their mechanism of action. This review provides a reference for related research and looks ahead to future directions.

N- and S-doped CQDs were prepared using L-cysteine as a precursor. Different NS-CQDs/g-C₃N₄ composite photocatalysts were formed by modifying graphite-phase carbon nitride with different contents of NS-CQDs using a hydrothermal method. The morphology, constituent elements and functional groups of the composite photocatalysts were analyzed by SEM, EDS, TEM, Mapping, XRD and FT-IR as a proof of its successful preparation. Meanwhile, it was characterized by PL, UV-Vis DRS and electrochemical impedance, which proved that the CQDs could be used as an electronic memory in the composite system to accelerate the electron transfer induced by the photo-excitation of g-C₃N₄ and effectively inhibit the recombination of e⁻-h⁺ improvement of the photocatalytic activity of g-C₃N₄. The stability of the composite photocatalysts under different conditions and the photodegradation activity of Rh B under visible light were investigated. It was found that the photocatalytic degradation efficiency of rhodamine B by NS-CQDS-modified g-C₃N₄ was significantly higher than that of pure g-C₃N₄, which could reach 90.82%, and its degradation rate was 3.5 times higher than that of pure g-C₃N₄. It was demonstrated by free radical trapping experiments that ·OH and ·O₂⁻ were the main active species in the photocatalytic degradation process, in which ·O₂⁻ played a guiding role.

Against the background of the vigorous development of materials science and the deep cross-infiltration in many fields, a new medicine food homology, carbon dots (herein combined and abbreviated as MFH-CDs), has sprung up, showing great potential. This review used ChatGPT 4.0 to collect background information related to carbon dots, focusing on the common rich medicinal and food resources such as Lycium barbarum, Chinese yam, honeysuckle, and Ganoderma lucidum. These carbon dots are synthesized by hydrothermal synthesis, microwave radiation, and pyrolysis, which have the advantages of small particle size, high quantum yield, and low cytotoxicity. Recent studies have found that MFH-CDs have great application potential in biosensors, biological imaging, and drug delivery. In this paper, the characteristics of preparing carbon dots from different medicinal and edible resources and their applications in biology in recent years are reviewed, which provides in-depth guidance for the research and application of carbon dots from medicinal and edible biomass, helps it shine in multidisciplinary fields, and opens a brand-new journey from traditional medicinal and edible culture to cutting-edge technology application.

By using melamine as a precursor for the copolymerization process, g-C₃N₄ and g-C₃N₄/TCNQ/Eu complexes with various amounts of doping were created. These complexes were then examined using XRD, FT-IR, SEM, TEM, XPS, PL, UV-vis, and I-T. The degradation rates of pefloxacin (PEF), enrofloxacin (ENR), and ciprofloxacin (CIP) were 91.1%, 90.8%, and 93.2% under visible light (λ > 550 nm). The photocatalytic performance of the composite was analyzed, and the best effect was obtained for CIP photocatalysis when Eu doping was 3 mg at 20 °C and pH 7. Kinetic analysis showed that there was a linear relationship between the sample and the photocatalytic time, and the degradation rate was about 5 times that of g-C₃N₄. The cyclic stability of the g-C₃N₄/TCNQ/Eu composite sample was found to be good through repeated experiments. UPLC-MS visualizes the degradation process of CIP. The extremely low stability of piperazine ring induced subsequent degradation, followed by the fracture of quinolone ring promoting the complete decomposition of CIP.