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Integration of novel bio-/nanostructures as effective sensing platforms is still of great significance for robust and rapid analysis. Herein, a novel metal-organic framework-derived NiCo2O4 was synthesized via a feasible templating method. Significantly, redox couples of both Ni3+/Ni2+ and Co3+/Co2+ provided richer oxidation-reduction reactions, thereby leading to an enhanced catalytic activity. Furthermore, NiCo2O4 as an enzyme mimic with peroxidase-like activity and oxidase-like activity could oxidize colorless thylbenzidine (TMB) to blue oxTMB in the absence of H2O2. Thus, a sensitive chromogenic sensing platform for detecting Fe2+, thiourea, cysteine (Cys), and epigallocatechin-3-gallate (EGCG) was proposed. The colorimetric detection methods exhibited great features of low limit of detection (LOD) and broad linear range. Owing to the complexation reaction, the chromogenic sensing system of TMB + NiCo2O4 + Cys achieved effective detection of Cu2+ and Mn2+ with the LODs of 0.0022 and 0.0181 mM, respectively. Developed detection methods with wide linear ranges of 0.008-0.1 mM for Cu2+ and 0.08-1 mM for Mn2+ had excellent practical potential. Similarly, the reaction system of TMB + NiCo2O4 + EGCG could achieve the colorimetric detection of Cu2+ and Fe3+. The great chromogenic sensing performance for detecting Cu2+ and Fe3+ with a broad linear range and a low LOD could be also realized.

It is of great significance to establish a simple method for sensitively detecting metal ions and antibiotics for food safety. Herein, two crystalline polyimide covalent organic frameworks (COFs) w...

Iron deficiency (ID) caused by blood loss and/or reduced iron absorption is a serious problem influencing health in inflammatory bowel disease (IBD). However, traditional iron supplements may fail to meet no side effect demands for ID of IBD; thus, a new iron supplementation is highly desired to be developed. Herein, for the first time, probiotic Lactobacillus alimentarius NKU556 with an iron-enriching ability was screened from Chinese traditional fermented food then employed to intervene DSS-induced colitis with bioluminescence tracing in mice. As expected, oral administration with NKU556-Fe can remarkably enhance the expression of tight junction proteins and effectively reduce the pro-inflammatory cytokines as well as the oxidative stress on DSS-induced colitis in mice. Meanwhile, in comparison with the FeSO4 group, the intake of NKU556-Fe could suppress the expression of hepcidin derived from the liver and reduce the degradation of FPN1, thereby leading to the increase in the iron absorption of colitis in mice. According to the bioluminescence result, it was believed that the beneficial effects of oral administration with NKU556/NKU556-Fe on DSS-induced colitis in mice were hardly related to its metabolites but associated with its own function. These results concluded that the oral administration of NKU556-Fe could relieve colitis inflammation and increase iron absorption. In summary, current work not only proposed a novel mediation strategy for IBD but also offered some inspirations for future treatment of extraintestinal complications.

Colorectal cancer is one of the leading causes of cancer incidence and mortality worldwide. Early diagnosis and treatment of colorectal cancer is beneficial to improve the therapeutic efficacy and ...

(–)-Anisomelic acid (AA), isolated from Anisomeles indica (L.) Kuntze (Labiatae) leaves, is a macrocyclic cembranolide with a trans-fused α-methylene-β-lactone motif. Cytopathic effect assays showed that the anti-SARS-CoV-2 effect of AA (IC50 = 4.3 μM) is comparable to that of remdesivir (IC50 = 2.1 μM), and more potent than that of molnupiravir (IC50 = 27.8 μM). Challenge studies in SARS-CoV-2-infected K18-hACE2 mice showed that orally administration of AA and remdesivir can both reduce the viral titers in the lung tissue at the same level. To facilitate drug discovery, we used a semisynthetic approach to shorten the project timelines. The enantioselective semisynthesis of AA from the naturally enriched and commercially available starting material (+)-costunolide was achieved in five steps with a 27% overall yield. The developed chemistry provides opportunities for developing AA-based novel ligands for selectively targeting proteins involved in viral infection.

Tea polyphenols (TP) possess the ability to regulate dyslipidemia and gut microbiota dysbiosis. However, the underlying mechanism is still elusive. The present study explored the intervention of TP on high fat diet induced metabolic disorders, gut microbiota dysbiosis in mice, and the underlying intestinal mechanism. As a result, TP significantly ameliorated hyperlipidemia, improved the expression levels of hepatic lipid metabolism genes, and modulated gut microbiota. The underlying mechanism was supposed to rely on the maintaining of intestinal redox state by TP. Intestinal redox related indicators were significantly correlated with the distribution of gut microbiota. An unidentified genus of Lachnospiraceae, Bacteroides, Alistipes, and Faecalibaculum were identified as the biomarkers for intestinal redox state. Importantly, different dosages of TP modulated intestinal redox state and gut microbiota in varied patterns, and an overdose intake attenuated the beneficial effects on gut health. Our findings offered novel insights into the mechanism of TP on intestinal homeostasis.

An in vivo probing strategy that can real-time and in situ trace target probiotics inside the living body is herein proposed by employing plasmid-like DNA as in-taken assistance, persistent luminescence nanophosphors (PLNPs) as optical labeling, and background-free fluorescence bioimaging as signal readout. PLNPs with superlong afterglow and excellent biocompatibility and stability were surface-modified by DNA molecules with a specific sequence, which greatly promoted the nanoparticle penetration into the bacteria and facilitated the in vivo bioimaging with high sensitivity and signal-to-noise ratio. Compared with the previous surface-labeling strategy by antibody recognition, the in-taken optical labeling demonstrated improved stability, and reached ideal results of real-time and in situ monitoring the in vivo behaviors of target probiotics, supporting the further development of in vivo investigation methodology for foodborne probiotics. Moreover, such a strategy offers a promising platform that leverage nanoscience to food nutrition as well as food-safety research, aiming to collect more accurate and fresh information from the living body.

Merocyanines adsorbed into the mesopores of mSiO2 shell of NaYF4: 20% Yb, 2% Er, 0.2% Tm nanocrystals are demonstrated as ratiometric upconversion luminescence (UCL) probe for highly selective detection of HS(-) in living cells through inhibition of energy transfer from the UCL of the nanocrystals to the absorbance of the merocyanines. The UCL probe has been used for ratiometric sensing of H2S with high sensitivity and selectivity.