Integration of three non-interfering SERS probes combined with ConA-functionalized magnetic nanoparticles for extraction and detection of multiple foodborne pathogens.

A sandwich-structured SERS biosensor has been constructed for simultaneous detection of multiple pathogenic bacteria, consisting of non-interfering SERS probes for bacterial labeling and ConA-functionalizd magnetic nanoparticles for bacteria extraction. A the preparation method of PP3 SERS probe with high Raman activity is reported for the first time. Since the PP3 SERS probe has a very strong Raman peak at 2081 cm-1 in the "Raman silent region," the mixed SERS probe formed with MP1 and DP2 can meet the needs of multiple foodborne pathogen detection. Significantly, S. aureus, E. coli, and P. aeruginosa can be successfully extracted upon external magnetic field, and the limit of detection (LOD) is 1 CFU‧mL-1, lower than that of the congeneric detectors. This work paves a new way for the construction of a novel detector and absorbent for different bacteria in complex samples by using SERS probe.

Combining multisite functionalized magnetic nanomaterials with interference-free SERS nanotags for multi-target sepsis biomarker detection.

Surface-enhanced Raman scattering (SERS) is an ultra-sensitive vibration spectroscopy technology, with the advantages of multi-index and non-destructive quantitative detection, has attracted much attention in the joint detection of biomarkers. A novel SERS biosensor with multisite capture and interference-free quantification was designed for the joint detection of the sepsis biomarker interleukin-6 (IL-6) and procalcitonin (PCT). This biosensor had two interference-free core-shell SERS probes with highly efficient electromagnetic enhancement and a multisite functionalized magnetic nanomaterial with high adsorption capacity. They formed sandwich structure with the targets through boronic affinity and immunoreaction, and the multi-target quantitative analysis of biomarkers in serum was performed using a portable Raman spectrometer in the Raman-silent region. The SERS biosensor was exhibited highly sensitive with detection limits of 0.584 and 2.99 pg/mL for IL-6 and PCT, respectively. In addition, it exhibited excellent selectivity and specificity even with the interference of other proteins. As this SERS method showed excellent performance in the detection of sepsis, it has great potential for multi-index detection in clinical diagnosis of major diseases.

FPBA-modified magnetic nanoparticles combined with Au@AgNPs for label-free SERS detection of foodborne pathogens in milk.

We report a low-cost and highly sensitive label-free SERS biosensor for pathogen detection. Herein, this study prepared 4-formylphenylboric acid (FPBA) functionalized magnetic nanoparticles to adsorb pathogenic bacteria through boric acid affinity principle, and used aptamer modified Au@AgNPs as SERS substrate to specifically combine with pathogenic bacteria to form a sandwich structure. The pathogenic bacteria were detected by portable Raman spectrometer for SERS detection, and the fingerprint signals of pathogenic bacteria were analyzed by principal component analysis (PCA) to achieve the purpose of classification and identification of pathogenic bacteria. Under the optimized conditions, the SERS detection of Staphylococcus aureus (S. aureus) was 102 âˆ¼ 106 CFU/mL (R2 = 0.9925), and the limit of detection (LOD) was 34 CFU/mL. The linear range of Escherichia coli (E. coli) showed a good linear relationship in the range of 102 âˆ¼ 106 CFU/mL (R2 = 0.9993), and the LOD was 18 CFU/mL. The whole detection process was used the portable Raman spectrometer, which makes it suitable for the application of point-of-care testing (POCT).

miR-93-5p suppresses ovarian cancer malignancy and negatively regulate CCND2 by binding to its 3'UTR region.

Ovarian cancer is the most fatal gynecological cancer worldwide, yet the fundamental mechanism of malignancy acquisition in ovarian cancer remains unknown. miRNA has been implicated to a variety of diseases, including cancer initiation and progression. Cyclin-D2 (CCND2) is ubiquitously implicated in cancer uncontrol cell proliferation. Bioinformatic research revealed that CCND2 is a candidate gene for miR-93-5p with a binding site in its 3'UTR region in the current study. Using our ovarian cancer sample, we verified that miR-93-5p is negatively correlated with CCND2 mRNA and protein levels. Luciferase report assay revealed miR-93-5p inhibits CCND2 production through binding to the 3'UTR region. The expression of miR-93-5p in ovarian cancer patient samples was then determined, and a survival analysis was performed. Our findings showed that miR-93-5p is downregulated in ovarian cancer and is a favorable predictive factor in ovarian cancer patient. CCK8 assay, wound healing assay and flow cytometry-based cell cycle and apoptotic cell analyses were employed here. We found that miR-93-5p suppresses ovarian cancer cell proliferation and migration while enhances cell death. Our research certified that miR-93-5p reduces ovarian cancer malignancy by targeting CCND2.

Anti-Diabetic Indole-Terpenoids From Penicillium sp. HFF16 Isolated From the Rhizosphere Soil of Cynanchum bungei Decne.

Finding novel anti-diabetic compounds with effective suppression activities against hepatic glucagon response is urgently required for the development of new drugs against diabetes. Fungi are well known for their ability to produce new bioactive secondary metabolites. As part of our ongoing research, five new indole-terpenoids (1-5), named encindolenes D-H, were isolated from the fungus Penicillium sp. HFF16 from the rhizosphere soil of Cynanchum bungei Decne. The structures of the compounds were elucidated by spectroscopic data and ECD analysis. In the anti-diabetic activity assay, compounds 1-5 could inhibit the hepatic glucose production with EC50 values of 17.6, 30.1, 21.3, 9.6, and 9.9 µM, respectively, and decrease the cAMP contents in glucagon-induced HepG2 cells.