PFA made substrate showed better limits of detection (LODs) compared to that of wood made substrate. The LOD values for most of the target analytes were ranging from 20.00 ± 0.91 to 200.25 ± 9.04 pg with RSD values ≤ 5% except for pharmaceutical tablets where only depletion amounts were estimated. The LOD value of cocaine in urine was 39.88 ± 1.65 pg with RDS ≤4.56% showed to be a very promising analytical tool for analysis of drugs of abuse in biological samples under ambient conditions. Drugs of abuse, pharmaceuticals, spinosad, cholesterol, rhodamine B, glucose and amino acids were detected mostly as their protonated molecular ions while RDX and HMX were detected as their molecular cluster/adduct ions as [M + NO2]- and [M + NO3]-, and AN was detected as a cluster ion of HNO3 with NO3-, [HNO3 + NO3]-, without suffering from fragmentation. An effective mechanism of the enhanced sensitivity of the tribodesorption-DBDI-MS system in analyzing the nonvolatile compounds has been discussed.The procedure for determination of 21 macro- and trace elements - Li, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Cu, Zn, Se, Sr, As, Cd, Sb, Ba, Pb and U - in human fetal urine by inductively coupled plasma mass spectrometry (ICP-MS) was developed and validated. The application of a micronebulizer and a dynamic reaction cell (DRC) allowed to perform a full analysis of small volumes (200 μL) of urine collected from human fetuses without the need for sample digestion with closed microwave systems. The procedure and ICP-MS instrument was thoroughly optimized in order to reliably determine both macroelements and ultra-trace concentrations of elements. The internal standard method (Ge, Rh and Tb) was applied in order to encompass signal drift and non-spectral interferences. The rules of metrology were used in order to ensure the quality of the results (1) the procedure was validated, (2) the uncertainty of the measurement results was estimated and (3) the traceability of the measurement result was established by using the certified reference material with matching matrix (Seronorm Trace Elements Urine L-1). Also, the analyte addition method to the artificial urine was employed for additional confirmation of trueness of the procedure. The selected parameters of the procedure were as follows (a) limits of detection - (0.00023-53 μg L-1) for U and Ca, respectively, (b) recoveries of the reference value - 81%-136% for Mn and Cd, respectively (c) linearity expressed as R - greater than 0.999, and (d) expanded relative uncertainties (k = 2) - 13%-66% for Sr and Cd, respectively. The developed and validated procedure was applied to 58 samples of urine collected from human fetuses. The samples were diluted with nitric acid and analyzed without further treatment. The procedure allowed to reliably determine both macro- and trace elements in very low volume of sample in a single analytical run.An ultra-small and highly efficient spectral-detection system for four emission points was developed by integrating an injection-molded-plastic four-lens array, a seven-dichroic-mirror array, and an image sensor as one device. The seven-dichroic-mirror array was further miniaturized compared to our previous four-dichroic-mirror array by measures including reduction of the thickness of each dichroic mirror from 1.0 to 0.5 mm. As a result, the system enables highly sensitive and low-crosstalk seven-color detection of laser-induced fluorescence from four emission points of a four-capillary array. This capability allows simultaneous quantification of up-to-seven fluorophores concurrently present in each capillary. Sanger DNA sequencing and STR genotyping by four-capillary-array electrophoresis were experimentally demonstrated by the system.Abnormal O-linked N-acetylglucosamine (O-GlcNAc) concentrations have been associated with many diseases, but the lack of accurate detection method limited O-GlcNAc to be used as a biomarker in clinical diagnosis. Then O-GlcNAc transferase (OGT) has drawn researchers' attention as it closed related to the level of O-GlcNAc and be considered to be a promising new target for diseases diagnosis. Nevertheless, the existing OGT detection methods are either need labeling or the sensitity can not meet the needs of clinic testing. Herein, a label-free and sensitive SPR biosensor was developed for accurate detection of OGT based on a multi-functional peptide. The designed peptide contains three recognition sites, one is the cleavage site of protease K, one is the O-GlcNAcylated site by OGT, and another is six histidine which be used as the signal report probe to recognize Ni2+. The immobilized peptide would be cleavaged by proteinase K, then the His-tag residue part will leave the surface of Au film, resulting less His-tag could bind to Ni2+ and a small SPR signal would be record. If the peptide is O-GlcNAcylated by OGT, the cleaving reaction would be limited due to the adjacent site of O-GlcNAcylation. Then more His-tag can be left on the Au film and a bigger SPR signal could be record, this signal is associated with the concentration of OGT. Utilizing the change of the peptide configuration as a signal report probe for OGT detection not only avoids labeling of peptide, but also makes the method more sensitive. The determination linear range of OGT is from 2.00 × 10-13 to 5.00 × 10-8 M with a detection limit of 1.19 × 10-13 M, and the separation of two enzyme reactions ensured the high selectivity of the method. Finally, the sensing system was successfully used for OGT detection in blood samples with satisfied recovery. In summary, the label-free SPR platform for accurate detection of OGT in real samples is helpful to promote OGT serve as a biomarker for early clinical diagnosis of O-GlcNAc related diseases.Stable blue fluorescent nitrogen doped carbon dots (N-CDs) with a very high quantum yield up to 81% has been reported for the first time. Novel N-CDs were synthesized through an efficient and rapid one-step hydrothermal synthesis process from diethylenetriamine as nitrogen source and a novel carbon source trans-aconitic acid. The nanosized particles of N-CDs were in the range of 2-8 nm and uniformly distributed in molecular level. https://www.selleckchem.com/products/gsk-lsd1-2hcl.html The N-CDs showed high selectivity toward Fe3+ with low detection limit of 10.42 nmol L-1 (with corresponding linear range of 2-50 μmol L-1) enabling them for ion detection application and also exhibited high fluorescence stability in extreme pH conditions. Novel N-CDs also presented a green emission shift under acidic condition (pH~2) which makes them a potential sensing probe for security papers, food packaging and bio-medical detection sensors. A security paper sensor device has been fabricated and its operation function has been validated by making real time detection of color. The novel and facile to manufacture carbon dots has potential applications ranging from biological nano-sensors for security document to color-switch sensing and bio-imaging.