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33 due to the formation of HgS. The photocurrent decrease is linear to the concentration of Hg2+ in the range from 10-11 to 10-6 g/mL, with the limit of detection of 3.2 pg/mL. High accuracy and good reproducibility are realized in the real sample analysis of urine, river water, and sea water. The integration of oxygen defect engineering and direct Z-scheme electron transport principle provides a new avenue for fabricating high performance photoelectrochemical materials, which can be further combined with bio-recognition strategy for the ultrasensitive detection of biological molecules.Oxidized unsaturated fatty acids - i.e. eicosanoids and other oxylipins - are lipid mediators involved in the regulation of numerous physiological functions such as inflammation, blood coagulation, vascular tone and endothelial permeability. They have raised strong interest in clinical lipidomics in order to understand their role in health and diseases and their use as biomarkers. However, before the clinical translation, it is crucial to validate the analytical reliability of oxylipins. This notably requires to assess the putative artificial formation or degradation of oxylipins by (unsuitable) blood handling during plasma generation, storage and sample preparation. Using a liquid chromatography-mass spectrometry method covering 133 oxylipins we comprehensively analyzed the total (free + esterified) oxylipin profile in plasma and investigated the influence of i) addition of additives during sample preparation, ii) different storage times and temperatures during the transitory stage of plasma generation and i samples were stored at -80 °C for 15 months. Overall, we demonstrate that total plasma oxylipins are robust regarding delays during plasma generation and long-term storage at -80 °C supporting the application of oxylipin profiling in clinical research.A quick, highly selective and sensitive method for the determination of DNA was constructed based on the recovery of red fluorescence of carbon dots quenched by a ruthenium complex (Ru (bpy)2 (dppz)2+, bpy = 2,2'-bipyridine; dppz = dipyrido [3.2-a2',3'-c]phenazine). The carbon dots showed two emission peaks at 450 and 683 nm under excitation wavelength of 420 nm. After addition of Ru (bpy)2 (dppz)2+, the fluorescence of carbon dots at 683 nm was markedly quenched. Due to the stronger interaction between DNA and Ru (bpy)2 (dppz)2+, the quenched fluorescence of carbon dots was recovered with DNA added. Under the optimum conditions, there was a good linear relationship between the degree of fluorescence recovery of carbon dots and DNA concentration in range of 0.0150-9.60 μg mL-1. The detection limit was 0.00536 μg mL-1. The carbon dots were successfully applied to detect DNA in the simulated sample and the spiked recoveries were between 97.4% and 106%.In this work, we applied laser-induced breakdown spectroscopy (LIBS) to estimate the amount of toxic heavy metals (Pb, Cr, Ni) in five different brands of face foundation powders available in the local market using standard calibration curve (CC)-LIBS approach. These samples contain toxic elements like lead, chromium, nickel which are highly carcinogens to cause eczematous and atopic dermatitis. The strongest atomic transition lines of lead (405.7 line), chromium (425.4 nm line), and nickel (336.9 nm line) were used as spectral markers to simultaneously detect these three heavy metals in face powder samples. The LIBS experimental parameters (delay time, laser energy, and focusing lens to target spacing) were optimized to enhance the signal to noise ratio in the resulting LIBS spectra. The consequence of self-absorption on the marker peaks used in the LIBS analysis was investigated and found to be insignificant. We calibrated our LIBS system for these three heavy metals, whose levels were found above the permissible limits. The face foundation powder used every day augments up to considerable exposure of heavy metals in the human body which could cause many skin disorders. Our LIBS quantitative results were also cross-validated by analysis using a standard analytical technique known as inductively coupled plasma-optical emission spectroscopy (ICP-OES). This study is highly significant due to the excessive use of cosmetic products especially face powder that could affect the health of millions of people around the globe.Ambient ionization-based techniques hold great potential for rapid point-of-care applicable metabolic fingerprinting of tissue and fluids. Hereby, feces represents a unique biospecimen as it integrates the complex interactions between the diet, gut microbiome and host, and is therefore ideally suited to study the involvement of the diet-gut microbiome axis in metabolic diseases and their treatments at a molecular level. We present a new method for rapid ( less then 10 s) metabolic fingerprinting of feces, i.e. laser-assisted rapid evaporative ionization mass spectrometry (LA-REIMS) with an NdYAG laser (2940 nm) and quadrupole Time-of-Flight mass spectrometer as main components. The LA-REIMS method was implemented on mimicked crude feces samples from individuals that were assigned a state of type 2 diabetes or euglycaemia. Based on the generated fingerprints, enclosing 4923 feature ions, significant segregation according to disease classification was achieved through orthogonal partial least squares discriminaas an expedient strategy for rapid metabolic fingerprinting of feces, whereby potential implementations may relate, but are not limited to differential diagnosis and treatment efficacy evaluation of metabolic diseases. Yet, LC-HRMS remains essential for in-depth biological interpretation.Cocaine is one of the most frequently used illicit drug in the world. Therefore, the development of simple and fast methods for the detection of cocaine and common adulterants, diluents and impurities are extremely important in forensic investigations. The present study describes, for the first time, a method based on capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D) for the rapid (2.5 min) and simultaneous quantification of cocaine, levamisole, lidocaine, carbonate, borate, chloride, nitrate, nitrite and sulphate. In the experiment, anions were separated in co-electroosmotic mode and cations in counter-electroosmotic mode employing a buffer solution composed by 10.0 mmol L-1 TAPS, 12 mmol L-1 NaOH and 0.2 mmol L-1 CTAB as the background electrolyte (pH = 8.8). The developed CE method demonstrated some interesting analytical characteristics such as (i) a simple sample pretreatment step (only dilution in water and filtering), (ii) high-throughput screening (24 injections h-1), (iii) proper recovery values (between 72 and 118%), and (iv) an inter-day precision of less than 7% for all analytes. The procedure was successfully applied in the analysis of seized cocaine samples collected by the Integrated Forensics Post (PPI) of the Minas Gerais Civil Police (Uberaba, Minas Gerais State, Brazil), during the year of 2018.A porphyrin structure carbon dots (CDs) with red fluorescence is prepared by the reaction of terephthalaldehyde with pyrrole under the trifluoroacetic acid catalyst. The CDs with an average particle size of 5.70 nm are red-emission with a maximum fluorescent wavelength at 650 nm due to the large conjugate structure of the porphyrin ring, giving rise to a quantum yield of 14%. The aldehyde groups in CDs make self-aggregation possible, and promote the effective coating of CDs around Transferrin (Trf) via the Schiff base reaction, forming CDs@Trf nanocomposites with a particle size of 19.7 nm. Trf can specifically target cells with Trf receptors on the surface of cell membrane. CDs@Trf exhibits stable red-emission in low polarity solvents, and are able to generate singlet oxygen (1O2), which facilitates cell imaging and photodynamic therapy. In vitro cell experiments demonstrate that CDs@Trf greatly inhibits the growth of tumor cells under laser irradiation at 635 nm. After incubation of 3 mg mL-1 CDs@Trf with Bend.3 cells, the survival rate of the cells is only 26% under laser irradiation of 4.78 mW cm-2 for 5 min.The endocannabinoid system has been implicated in the dynamic regulation of the stress response, fear memory formation, and inflammatory processes. Endocannabinoids (eCBs) and N-acylethanolamines (NAEs) are primarily quantified from serum or cerebrospinal fluid representing acute measures, while no validated method for the quantification of long-term integrated eCBs and NAEs concentrations exists. We here present an online solid phase extraction-liquid chromatography-mass spectrometry method (LC-MS/MS) for quantification of long-term integrated eCBs and NAEs in human hair and examine their association with burnout, depression, and anxiety symptoms. Hair samples were washed with isopropanol and endocannabinoids were extracted from 7.5 mg hair by methanol incubation. A column switching strategy for online solid phase extraction (SPE) was applied, followed by mass spectrometer detection. eCBs and NAEs levels were determined in 207 hair samples from an ongoing longitudinal study and related to individual burnout, depression and anxiety symptoms. The limits of detection were between 0.06 and 6.0 pg mg-1, the recoveries of this method were between 87.2% and 114.2%. Hair AEA levels showed a negative correlation with burnout and anxiety symptoms. Participants with clinically relevant burnout and anxiety symptomatology exhibited lower hair AEA levels compared to those participants with low burnout and anxiety symptomatology, while for depressive symptomatology no association was identified. The presented LC-MS/MS method provides a highly specific analytical strategy for the detection of eCBs and NAEs concentrations in human hair and is thus likely to further shed light on the temporal dynamics of eCBs and NAEs secretion. The analysis of eCBs and NAEs in hair emerges as useful strategy in biopsychological research and as a valid and easily implementable method for the retrospective assessment of cumulative long-term eCBs and NAEs secretion.This review focuses on optical nanosensors based on silver nanoparticles (Ag NPs) and demonstrates their applications in the determination of pharmaceutical compounds in the last decade. Such optical sensors have received high attention in the analytical field owing to their low cost and simplicity since they do not require any complex or expensive instrumentation. This article reviews Ag NP-based optical methods for the determination of pharmaceutical compounds from 2010 to 2020. The reported optical methods are classified into four types spectrophotometry, spectrofluorimetry, scattering and chemiluminescence. Ag NPs play different roles in the different sensing platforms used by these methods, the details of which are carefully explained in this review. Moreover, the relevant analytical parameters of the developed methods are categorized by role and tabulated. It is hoped that this review will stimulate further research in this field with similar nanostructures.Postharvest fruit decay is caused by fungal pathogens and leads to major losses. In this study, specific mRNA sequences that are upregulated in the fungus Colletotrichum gloeosporioides during its quiescent stage in fruits, were identified using a CMOS sensor. The identification process was based on sandwich approach, where strands complementary to the C. gloeosporioides mRNA sequences (quiescent stage-specific) were immobilized on the CMOS surface, and exposed to the target complementary reporter strands. In the presence of a target sequence, the reporter strand (linked to the enzyme horseradish peroxidase (HRP)) was left in the system and a measurable light signal was produced. The complementary strands specifically anneal to the mRNA in the sample. The sensitivity of the technology was assessed by mRNA sequences isolated from C. gloeosporioides, and identified as 10 nM RNA. The effect of the pathogenicity state on the sensor performance was also evaluated. The CMOS sensor could detect quiescent fungi, which are barely detectable by other means.