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A long-lived room temperature phosphorescence (RTP) carbon quantum dots (P-CDs) with ultraviolet/visible (UV/Vis) light photoresponsive oxidase-like nanozyme were synthesized to achieve higher photosensitive oxygen activation. Then the P-CDs were made into P-CDs/PVA films, which effectively prolonged the preservation period of fruits under photodynamic antibacterial action. [Display omitted] • One-step hydrothermal synthesis of long-lived room-temperature phosphorescent P-CDs. • The ultraviolet/visible light photoresponsive oxidase-like nanozyme activity. • P-CDs generate singlet oxygen through energy transfer under illumination. • The excellent photodynamic antibacterial property of P-CDs. • P-CDs/PVA films remarkably extend the shelf life of fruits under photosensitization. In this study, a novel long-lived room-temperature phosphorescent (RTP) carbon dots (P-CDs) with the properties of ultraviolet/visible (UV/Vis) light photoresponsive oxidase-like nanozyme were synthesized from diethylenetriaminepentaacetic acid and through a one-step hydrothermal method. P-CDs were used as a light-driven oxidative-like enzyme for antimicrobial studies. The results showed that under UV/Vis light irradiation, P-CDs could efficiently convert O 2 into 1O 2 , and the strong oxidizing property of 1O 2 greatly enhanced the growth inhibition of P-CDs on Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). Meanwhile, P-CDs exhibited good photodynamic antifungal properties against Botrytis cinerea (B. cinerea). Then the P-CDs were made into P-CDs/PVA films, which effectively prolonged the preservation period of fruits under photodynamic antibacterial action. The good biocompatibility and efficient photosensitive oxygen activation can make P-CDs a more practically useful oxidase-like nanozyme. [ABSTRACT FROM AUTHOR]

PFMM-MIPs were prepared, and RTP and RF double-channel specific analysis of double targets was achieved. [Display omitted] • Phosphorescent/fluorescent dual-channel molecularly imprinted polymers were prepared. • Malachite green was determined by room temperature phosphorescence. • Tartrazine was determined by ratiometric fluorescence. • It exhibits excellent sensitivity, selectivity, and recovery. The photoluminescent properties of Mn-doped ZnS quantum dots were fully exploited, and room-temperature phosphorescence (RTP)-ratiometric fluorescence (RF) magnetic mesoporous molecularly imprinted polymers (PFMM-MIPs) were prepared by integrating molecular imprinting technology. RTP was used to detect malachite green (MG). The fluorescence at 420 nm and the peak at 590 nm in the fluorescence mode were used as the response reference signals respectively to detect tartrazine (TZ). The linear responsive range and detection limit of MG were 0.01–150 μM and 4.3 nM, and these of TZ were 0.05–80 μM and 23.7 nM. RTP, which can avoid the interference of background fluorescence, and RF with self-calibration ability can both largely weaken the matrix effect. This work enables single-probe-type MIPs to achieve dual-target analysis via RTP and RF. This method provides excellent sensitivity, specificity, recovery and recyclability, and is expected to be prospectively applied in the fields of food, environment and biological analyses. [ABSTRACT FROM AUTHOR]

Molecular imprinting technology (MIT) and Mn-doped ZnS room-temperature phosphorescent quantum dots (Mn-ZnS RTP QDs) were combined to create a molecularly imprinted polymer (MIP) (MIP-coated QDs) that could specifically identify malachite green (MG). The MIP-coated QDs and the target MG small-molecules formed a phosphorescent resonance energy transfer system, and the RTP intensity was weakened with the increasing MG concentration. The MG detection limit and detection range were 30.34 nM and 0.08–80 μM, respectively. The spiked recovery rates in MG detection from fish meat and natural water were 96–107% and 95–102%, respectively. The MIP-coated QDs integrated the RTP and the high selectivity of MIT, and avoided interference from the background fluorescence or scattering light in biological or environmental samples and from competitive substances. Thus, the new MIP-coated QDs can be used to specifically detect trace MG in fish meat or natural waters. [ABSTRACT FROM AUTHOR]

Mesoporous molecularly imprinted polymers (MIPs) containing mangnanese-doped ZnS quantum dots (Mn-ZnS QDs) were prepared for specific recognition and detection of 4-nitrophenol (4-NP). The Mn-ZnS QDs display orange room-temperature phosphorescence with excitation/emission peaks at 295/590 nm and a decay time of 2.0 ms. In the presence of 4-NP, the orange phosphorescence is strongly reduced. Phosphorescence drops linearly in the 0.1–100 μM 4-NP concentration range, and the detection limit is 60 nM. The detection limit is far lower than the maximally allowed 4-NP concentrations in surface water and drinking water as specified by the U.S. Environmental Protection Agency. The intraday (n = 5) and interday (n = 6) spiked recovery rates were 96.0–104.5% and 97.9–107.9%, respectively, with relative standard deviations of 0.7–4.8% and 1.8–7.5% respectively. These MIPs integrated the characteristic features of phosphorimetry and molecular imprinting. Potential interference by competitive substances, background fluorescence or scattered light are widely reduced. Graphical abstract Schematic presentation of the synthesis of phosphorescent molecularly-imprinted polymers. A novel probe with manganese-doped ZnS quantum dots (Mn-ZnS QDs) and 3-aminopropyl-triethoxysilane (APTES) as functional monomers and tetraethoxysilane (TEOS) as crosslinking agent was prepared for selective phosphorescence detection of 4-nitrophenol (4-NP). [ABSTRACT FROM AUTHOR]

With the advanced discoveries in the field of pathogenesis, a series of cerebral diseases, such as cerebral ischaemia, Alzheimer's disease, and depression, have been found to have multiple signalling targets in the microenvironment. Only a few existing agents have been shown to have curative effects due to this specific circumstance. In recent decades, active ingredients isolated from natural plants have been shown to be crucial for original drug development. Geniposide, mainly extracted from Gardenia jasminoides Ellis, is representative of these natural products. Geniposide demonstrates various biological activities in the treatment of cerebral, cardiovascular, hepatic, tumorous, and other diseases. The multiple protective effects of geniposide on the brain have especially drawn increasing attention. Thus, this article specifically reviews the characteristics of current models of cerebral ischaemia and illustrates the possible effects of geniposide and its pathogenetic mechanisms on these models. Geniposide has been shown to significantly reduce the area of cerebral infarction and alleviate neuronal damage and necrosis mainly by inhibiting inflammatory signals, including NLRP3, TNF-α, IL-6, and IL-1β. Neuronal protection was also involved in activating the PI3K/Akt and Wnt/catenin pathways. Geniposide was able to increase autophagy and inhibit apoptosis by regulating the function of mTOR in treating Alzheimer's disease. Geniposide has also been shown to act as a glucagon-like peptide-1 receptor (GLP-1R) agonist to reduce amyloid plaques and inhibit oxidative stress to alleviate memory impairment as well as synaptic loss. Moreover, geniposide has been shown to exert antidepressant effects primarily by regulating the hypothalamic–pituitary–adrenal (HPA) axis. Detailed explorations have shown that the biological activities of inhibiting inflammatory cytokine secretion, alleviating oxidative stress, and suppressing mitochondrial damage are also involved in the mechanism of action of geniposide. Therefore, geniposide is a promising agent awaiting further exploration for the treatment of cerebral diseases via various phenotypes or signalling pathways. [ABSTRACT FROM AUTHOR]