7 and 7.8 mg L-1; all of which were above the WHO recommended level of fluoride (0.8-1.5 mg L-1) in drinking water. This method can potentially be used for total fluorine determination and might be useful for fluorine speciation analysis when coupled with HPLC.Surface-enhanced Raman spectroscopy, due to its high sensitivity, unique vibrational fingerprint identification of molecules and easy operation, has been extensively applied in different fields. Aptamers, being the unique single stranded DNA/RNA sequences that can specifically recognize and seize the target analytes, combined with Surface-enhanced Raman spectroscopy (SERS), can offer potent multiplex detection capacity with high specificity and sensitivity. In this review, we summarize and classify the general working strategies of different types of aptamer-based SERS biosensors with diversified protocols which either take aptamer conformational change as intrinsic reporter, or make use of various extrinsic Raman reporters in different sensor designs via on/off approach, sandwich-type and magnetic nanoparticles (NPs)-assisted approach, and catalytic reaction assisted approach with amplification of alternative Raman signals. The advantages, applications and perspectives of these aptamer-based SERS biosensors are also discussed.Predictive models have been developed for the early identification of novel anabolic androgenic steroids and to obtain information on their molecular structure. To this purpose, gas-chromatographic and mass spectrometric characteristic parameters of 136 anabolic androgenic steroids have been specifically considered. Starting from Principal Component Analysis, different chemometric methods were applied, such as classification and clustering techniques, outlining a spectral and structural characterization for each steroid subclass, and considering the contribution of more than 30 variables. Mass spectrometric data on the TMS-derivatives of the target steroids were obtained by gas chromatography coupled to quadrupole-time of flight mass spectrometry using electron ionization. Steroids included in the training set were grouped in 5 subclasses according to their structural similarity, and the experimental data, processed by the chemometric models, allowed the identification of class-specific common fragments and spectral trends. The results of this study, validated on a test set of 21 steroids, have confirmed that the proposed approach allows tracing novel "designer anabolic steroids", including those previously unknown new structures that may have been designed and illicitly synthesized to be invisible to the current anti-doping tests.Cellular differentiation is a fundamental process in which one cell type changes into one or more specialized cell types. https://www.selleckchem.com/products/sb297006.html Cellular differentiation starts at the beginning of embryonic development when a simple zygote begins to transform into a complex multicellular organism composed of various cell and tissue types. This process continues into adulthood when adult stem cells differentiate into more specialized cells for normal growth, regeneration, repair, and cellular turnover. Any abnormalities associated with this fundamental process of cellular differentiation are linked to life-threatening conditions, including degenerative diseases and cancers. Detection of undifferentiated and different stages of differentiated cells can be used for disease diagnosis but is often challenging due to the laborious procedures, expensive tools, and specialized technical skills which are required. Here, a novel approach, called deep ultraviolet resonance Raman spectroscopy, is used to study various stages of cellular differentiation using a well-known myoblast cell line as a model system. These cells proliferate in the growth medium and spontaneously differentiate in differentiation medium into myocytes and later into myotubes. The cellular and molecular characteristics of these cells mimic very well actual muscle tissue in vivo. We have found that undifferentiated myoblast cells and myoblast cells differentiated at three different stages are able to be easily separated using deep ultraviolet resonance Raman spectroscopy in combination with chemometric techniques. Our study has a great potential to study cellular differentiation during normal development as well as to detect abnormal cellular differentiation in human pathological conditions in future studies.Quantitative bioimaging of Quantum Dots (QDs) uptake in single cells by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a challenging task due to the high sensitivity and high spatial resolution required, and to the lack of matrix-matched reference materials. In this work, high spatially resolved quantitative bioimaging of CdSe/ZnS QDs uptake in single HT22 mouse hippocampal neuronal cells and in single HeLa human cervical carcinoma cells is novelty investigated combining (a) the use of a ns-LA-ICP-Sector Field (SF)MS unit with mono-elemental fast and sensitive single pulse response for 114Cd+; and (b) the spatially resolved analysis of dried pL-droplets from a solution with a known concentration of these QDs to obtain a response factor that allows quantification of elemental bioimages. Single cells and dried pL-droplets are morphologically characterized by Atomic Force Microscopy (AFM) to determine their volume and thickness distribution. Moreover, operating conditions (e.g. spot size, energy per laser pulse, etc.) are optimized to completely ablate the cells and pL droplets at high spatial resolution. Constant operating conditions for the analysis of the single cells and calibrating samples is employed to reduce potential fractionation effects related to mass load effects in the ICP. A number concentration of CdSe/ZnS QDs between 3.5 104 and 48 104 is estimated to be uptaken by several selected single HT22 and HeLa cells, after being incubated in the presence of a QDs suspension added to a standard cell culture medium. Mono-elemental bioimaging at subcellular resolution seems to show a higher number concentration of the CdSe/ZnS QDs in the cytosol around the cell nucleus.