Gold nanoparticles/785 porous silicon photonic crystals (Au NPs/785 PSi PhCs) were used as substrates in combination with a low-concentration serum surface-enhanced Raman spectroscopy (SERS) detection scheme to obtain spectral signals from healthy individuals and cervical cancer patients. The best principal component scores were selected by principal component analysis (PCA) combined with linear discriminant analysis (LDA) and support vector machine (SVM) to analyze the spectral differences distinguishing healthy and cervical cancer patients. The accuracy of the two models was 97.9% and 96.9%, respectively. SERS technique based on Au NPs/785 PSi PhCs has great potential to improve the screening of cervical cancer.

Biomass-derived porous carbon (PC) loaded with precious metals have a synergistic enhancement effect on surface-enhanced Raman scattering (SERS). In this paper, PC containing various functional groups and large specific surface area, good stability and certain biocompatibility were prepared using tomato skins and introduced into the preparation of Ag nanoflowers (NFs) SERS substrates. Rhodamine 6G (R6G) was used as the Raman probe molecule to evaluate the sensing performance of Ag NFs@PC. The results showed that the stable dispersion and protective effect of PC on Ag NPs significantly improved the sensitivity and long-term stability of traditional Ag NFs. In practical application, Ag NFs@PC was further used to successfully achieve the quantitative analysis of trace methylene blue (10 ppt) and malachite green (10 ppt) in a lake water system. Therefore, SERS sensor Ag NFs@PC is expected to become a promising candidate sensor for detecting in the field of environment and food monitoring. Graphical abstract

Purpose: The lncRNA MIR155 host gene (MIR155HG) plays a role in the progression of several malignant cancers. However, the specific mechanisms of MIR155HG in glioma progression have not been clearly established. The purpose of this study was to investigate the function of MIR155HG in glioma at the transcriptome level and relationship with immune infiltration. Patients and Methods: Totally, 697 RNA-seq and 594 DNA methylation data were retrieved from The Cancer Genome Atlas (TCGA) dataset while 325 RNA-seq data were retrieved from the Chinese Glioma Genome Atlas (CGGA) dataset. The DNA methylation levels of MIR155HG CpG islands were assessed through bisulfite amplicon sequencing (BSAS). The regulatory mechanism of SP1 on MIR155HG was examined by chromatin immunoprecipitation (ChIP) and luciferase reporter assays. R language was used as the main tool for statistical analysis and graphical work. Results: MIR155HG was predominantly expressed in the isocitrate dehydrogenase (IDH) wild-type as well as mesenchymal subtype gliomas. Promoter methylation levels of MIR155HG in glioblastoma (GBM) were remarkably decreased compared with those in lower-grade glioma (LGG). In addition, there were negative correlations between promoter methylation levels and MIR155HG expressions but positive correlations with patients' overall survival. In vitro studies further revealed that MIR155HG expression was regulated by DNA promoter methylation and transcription factor (SP1) binding to the promoter. Moreover, there was a close association between MIR155HG expression and immune as well as stromal cell infiltrations, inflammatory activities, and immune checkpoints. Clinically, univariate and multivariate Cox analyses revealed that MIR155HG is an independent prognostic marker for glioma patients. Conclusion: Our results established that MIR155HG is a potential biomarker for prognosis and an immunotherapeutic target in glioma.

The BiFeO3 (BFO) thin films made by the electron beam evaporator are systematically investigated. As the most difficult part of this work, the preparation process is repeated until the optimal deposition power and elemental composition of BFO are obtained. With the help of X-ray diffraction and Raman spectroscopy, we specify precisely that the sample annealed at the temperature of 650 °C is the purest BFO phase with rhombohedral R3c structure. The Scanning Electron Microscopy images provide the surface morphology and cross-sectional thickness of each sample for the further performance analysis. With the aim of understanding the changes in the chemical bond structure of BFO samples at the different annealing temperatures, we applied X-ray photoelectron spectroscopy and the result indicates that the absorption of oxygen is increasing with the raising of the annealing temperature. Finally, we measured the magnetic property and resistivity of BFO samples to explore their applications. The saturation magnetization measurement shows the correlation between the magnetization of BFO and microstructures such as phase structure, grain size. Meanwhile, the electronic resistivity explains the close relationship between the resistivity and surface morphology.

As a rapid and non-destructive biological serum detection method, SERS technology was widely used in the screening and medical diagnosis of various diseases by combining the analysis of serum SERS spectrum and multivariate statistical algorithm. Because of the high complexity of serum components and the variability of SERS spectra, which often resulted in the phenomenon that the SERS spectrum of the same biological serum was significantly different due to the different test conditions. In this experiment, through the dilution treatment of the serum and the systematic test of the serum of all concentration gradients with lasers of wavelength of 785, 633 and 532 nm, the most suitable conditions for detecting the serum were investigated. The experimental results showed that only when the serum is diluted to low concentration (10 ppm), the SERS spectrum with high reproducibility and stability could be obtained, furthermore, the low concentration serum had weak tolerance to laser, and 532 nm laser was not suitable for serum detection. In this paper, a set of test scheme for obtaining highly stable serum SERS spectra was established by using high-performance gold nanoparticles (Au NPs) as the active substrate of SERS. Through comparative analysis of SERS spectrum of serum of normal people and cervical cancer, the reliability of the established low-concentration serum test program was verified, as well as its great potential advantages in disease screening and diagnosis.

Surface-enhanced Raman scattering (SERS), as a rapid, reliable and non-destructive spectral detection technology, has made a series of breakthrough achievements in screening and pre-diagnosis of various cancerous tumors. In this paper, high-performance gold nanoparticles/785 porous silicon photonic crystals (Au NPs/785 PSi PhCs) active SERS substrates were specially designed for serum testing, and realized highly sensitive detection of serum from healthy people, patients with cervical cancer and breast cancer. Based on the SERS spectra of the three groups of serum, the significant differences between the healthy group and cancer group at 1030 cm−1 and 1051 cm−1 were analyzed, and the similar but different serum SERS spectra of cervical cancer and breast cancer patients were compared. In addition, the spectral difference detected by SERS technology combined with a multivariate statistical algorithm was used to distinguish three kinds of serum. The serum SERS spectral sensitive bands were extracted by recursive weighted partial least squares (rPLS), and the three classification diagnosis models were established by combining orthogonal partial least squares discriminant analysis (OPLS-DA), linear discriminant analysis (LDA) and principal component analysis support vector machine (PCA-SVM) for synchronous classification and discrimination of the three groups of serum. The diagnostic results showed that the overall screening accuracy of three models were 93.28%, 97.77% and 94.78%, respectively. These above results confirmed that the Au NPs/785 PSi PhCs can realize super-sensitive detection of serum, and the established diagnostic model has great potential for pre-diagnosis and simultaneous screening of cervical cancer and breast cancer.

Developing a novel and simple route for the synthesis ultrasensitive and specific SERS substrates is highly desirable and technically important. Here, a magnetic ionic liquid (MIL) assisted strategy is developed, and the high-quality and ultra-sensitive MIL-gold nanoparticles/porous silicon (MIL-Au NPs/PSi) composite substrate were synthesized by a fast and cost effective strategy with the assistance of MIL (1-methyl-3-hexyl imidazole ferric tetrachloride ([C(6)mim]FeCl4). Fundamental SERS performance of this composite substrate was evaluated using rhodamine 6G (R6G). The results showed that MIL make the Au NPs/PSi have great advantages in synergetic enhancement and stability, and the hypersensitive detection of specific substances can be realized by selecting or designing IL. Based on the particularity of MIL ([C(6)mim] FeCl4's function and structure, arsenic was detected with MIL-Au NPs/PSi substrate. The detection limit can reach 0.5 ppb, and the standard curves with regression coefficients of 0.98527 and 0.98965 were established in the linear range of 2-80 ppb and 200-800 ppb. In a word, an advanced method for the preparation of high-performance and designable SERS substrate has been developed, which will certainly show promising applications in detection technology.

Solar energy hydrogen production is one of the best solutions for energy crisis. Therefore, finding effective photocatalytic materials that are able to split water under the sunlight is a hot topic in the present research fields. In addition, theoretical prediction is a present low-cost important method to search a new kind of materials. Herein, with the aim of seeking efficient photocatalytic material we investigated the photocatalytic activity of GaAs monolayer by the first principles calculation. According to the obtained electronic and optical properties, we primarily predicted the photocatalytic water splitting activity of GaAs monolayer, which the result further confirmed by the calculated reaction free energy. More remarkably, predicted carrier mobility of GaAs monolayer 2838 cm 2 V −1 s −1 is higher than 200 cm 2 V −1 s −1 of MoS 2 . Our finding provides a promising material for the development of renewable energy conversion and a new outlook for better designing of a superior photocatalyst for water splitting.