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A multifunctional surface-enhanced Raman scattering (SERS) platform integrating sensitive detection and drug resistance analysis was developed for Gram-positive bacteria. The substrate was based on self-assembled Ti3C2Tx@Au NPs films and capture molecule phytic acid (IP6) to achieve specific capture of Gram-positive bacteria and different bacteria were analyzed by fingerprint signal. It had advantages of good stability and homogeneity (RSD = 8.88%). The detection limit (LOD) was 102 CFU/mL for Staphylococcus aureus and 103 CFU/mL for MRSA, respectively. A sandwich structure was formed on the capture substrate by signal labels prepared by antibiotics (penicillin G and vancomycin) and non-interference SERS probe molecules (4-mercaptobenzonitrile (2223 cm−1) and 2-amino-4-cyanopyridine (2240 cm−1)) to improve sensitivity. The LOD of Au NPs@4-MBN@PG to S. aureus and Au NPs@AMCP@Van to MRSA and S. aureus were all improved to 10 CFU/mL, with a wide dynamic linear range from 108 to 10 CFU/mL (R2 ≥ 0.992). The SERS platform can analyze the drug resistance of drug-resistant bacteria. Au NPs@4-MBN@PG was added to the substrate and captured MRSA to compare the SERS spectra of 4-MBN. The intensity inhomogeneity of 4-MBN at the same concentrations of MRSA and the nonlinearity at the different concentrations of MRSA revealed that MRSA was resistant to PG. Finally, the SERS platform achieved the determination of MRSA in blood. Therefore, this SERS platform has great significance for the determination and analysis of Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

High performance platform for detecting ESBL-E. coil. [Display omitted] • Design of capture substrate to achieve stable, efficient capture of ESBL-E. coil. • Proposing of signal-enhancing structure and indirect method to detect ESBL-E. coil. • The platform has a good linear range and a detection limit of 10 CFU/mL. • A new method for the detection of ESBL-E. coil in milk. Drug-resistant bacteria is highly infectious and has been appearing in food in recent years threatening human health. Therefore, effective detection of drug-resistant bacteria is crucial. In this paper, an interference-free surface-enhanced Raman scattering (SERS) platform was developed for the detection of extended-spectrum β-lactamase E. coil (ESBL-E. coil). 4-mercaptomethylboronic acid (4-MPBA) was used as a capture molecule for drug-resistant bacteria, and self-assembled gold nanoparticles (Au NPs) were utilized to develop a high-performance SERS analytical platform for the detection of drug-resistant bacteria. Meanwhile, in order to obtain a lower detection limit and higher precision, Ti 3 C 2 T x , modified with 4-mercaptobenzonitrile (4-MBN) and Au NPs, was used for signal enhancement and indirect detection. The SERS platform detected signals from the Raman silent region, where there was no background signal from biological sources, eliminating the interference, a detection limit was 10 CFU/mL, with a wide dynamic linear range from 10-108 CFU/mL. Meanwhile, the stability, homogeneity and reproducibility were excellent. The precise quantification capability of the SERS platform was validated by the detection of ESBL-E. coil in milk. Therefore, the method holds great promise for the development of a stable and sensitive SERS platform for the detection of drug-resistant bacteria. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) have been reported to play crucial role in the airway inflammatory diseases. However, the involvement of miR-206 in airway inflammatory diseases is still uninvestigated. The study aimed to explore the effect of miR-206 on lipopolysaccharide (LPS)-induced inflammation injury in MRC-5 cells, and point out a potential relevance for chronic obstructive pulmonary disease (COPD). LPS was utilized to expose MRC-5 cells, then cell viability, cell migration, apoptosis, apoptosis-associated factors, as well as the concentrations and protein levels of IL-6 and IL-8 were explored. After transfected with miR-206 mimic and inhibitor, above parameters were reassessed in LPS-injured cells. Expression level of IRAK1 was examined in miR-206 mimic/inhibitor transfected cells by using RT-qPCR. The effect of IRAK1 on LPS-induced inflammation injury was investigated in MRC-5 cells after transfection with pc-IRAK1 and sh-IRAK1. The effects of miR-206 and IRAK1 on MEK/ERK and JNK pathways were determined by western blot assay. LPS significantly triggered inflammation injury in MRC-5 cells by inhibiting cell viability, suppressing the healing of scratches, inducing cell apoptosis, down-regulating Bcl-2 expression and up-regulating Bax, cleaved-Caspase-3 and cleaved-Caspase-9 expression, and concurrently increasing the concentrations and the protein levels of IL-6 and IL-8. MiR-206 overexpression aggravated LPS-induced inflammation injury in MRC-5 cells. Up-regulation of IRAK1 was observed in miR-206 mimic-transfected cells. Moreover, IRAK1 overexpression promoted LPS-induced inflammation injury in MRC-5 cells. MiR-206 activated MEK/ERK and JNK pathways by regulating IRAK1. MiR-206 promotes LPS-induced inflammation injury through regulation of IRAK1 in MRC-5 cells. • LPS induces inflammation injury in MRC-5 cells. • MiR-206 promotes LPS-induced inflammation injury in MRC-5 cells. • MiR-206 up-regulates IRAK1 expression in MRC-5 cells. • IRAK1 promotes LPS-induced inflammation injury in MRC-5 cells. • MiR-206 activates MEK/ERK and JNK pathways via regulating IRAK1. [ABSTRACT FROM AUTHOR]

A novel composite material Nb 2 C-Au NPs can enhance electromagnetic resonance and charge transfer resonance by synergistic conjugation and exhibits good SERS enhancement of dye molecules and biomolecules adenine. [Display omitted] • Nb 2 C-Au NPs nanocomposite was synthesized by electrostatic self-assembly method. • Composite material can synergistically enhance multiple SERS mechanisms. • Nb 2 C-Au NPs exhibits good SERS detection performance for dye molecules and adenine. Recent years, two-dimensional transition metal carbonitrides (MXene) have attracted much attention in the field of surface-enhanced Raman scattering (SERS). However, the relatively low enhancement of MXene is a major challenge. Herein, Nb 2 C-Au NPs nanocomposites were prepared by electrostatic self-assembly method, which have a synergistically conjugated SERS effect. The EM hot spots of Nb 2 C-Au NPs are significantly enlarged and expanded, while the surface Fermi level is decreased. This synergistic effect could improve the SERS performance of the system. Consequently, for the dye molecules CV and MeB, the detection limits reach 10−10 M and 10−9 M, respectively, while for biomolecule adenine, the detection limit is as low as 5 × 10−8 M. The results also show the good concentration-dependent linearity, uniformity, reproducibility and stability of SERS substrate. Nb 2 C-Au NPs could be a fast, sensitive and stable SERS platform for label-free and non-destructive detection. This work may expand the application of MXene based materials in the field of SERS. [ABSTRACT FROM AUTHOR]

Computed Tomographic Imaging Spectrometer (CTIS) has the advantages of both computed tomography technology and snapshot spectroscopy and has potential applications in many fields. However, the development of CTIS has been limited by the volume issues of key components. In consideration of the compact structure of the metamaterial, an all-dielectric metamaterial array is studied as an alternative to optimize the structure of CTIS. The array can be used for snapshot-type optical imaging, with a wide working range of 550 nm ∼ 1000 nm. At the same time, the system design and simulation technology are studied by using the array, which provides a useful reference for the development of micro imaging spectrometer based on metamaterial. • Using metamaterials to realize the miniaturization of CTIS. • The metamaterial is first used to realize the CGH of CTIS. • The micro CTIS adapts to the lens size of the mobile phone. [ABSTRACT FROM AUTHOR]