In this study, a magnetic molecularly imprinted polymer (MMIP (Fe3O4@SiO2-MIP)) was used for the dispersive magnetic solid-phase microextraction (d-MSP-μ-E) to design an easy and effective method for melatonin (MLT) extraction in the methanolic extract of Portulaca oleracea, human urine and plasma, and water samples. HPLC with UV detection was utilized, and pH, the type and volume of eluent, MMIP mass, and contact time were considered as effective factors in the study of MLT separation and pre-concentration. These factors were optimized by Plackett-Burman and multi-objective response surface methodology (RSM). The values were 10 mg, 14 min, 4.2, methanol, 0.180 mL, 2.5 min, for the MMIP mass, time of sorption, sample pH, eluent type, eluent volume, and time of elution, respectively. At the optimum conditions, the limit of detection (LOD) was 0.046 ng mL-1, and the limit of quantification (LOQ) was 0.156 ng mL-1. The sorption capacity of the proposed MMIP sorbent was 109.1 mg g-1 at the optimum conditions. Besides, linear dynamic range (LDR) was 0.2-4200 ng mL-1, and the precision of the method (RSD %) for triplicate measurements was less then 6.1%. The MMIP showed saturation magnetization of 19.75 emu g-1, resulting in fast separation of the sorbent. The sorption test revealed the high sorption capacity of the MMIP for MLT and its homogeneous binding sites. In all spiked levels (50, 100, 200, and 500 ng mL-1), 93.07-104.1% was the range obtained for the recovery of MLT. The relative selectivity factor (β) values of MLT/tryptophan, MLT/serotonin, MLT/ferulic acid, MLT/mefenamic acid, MLT/quercetin, MLT/luteolin, and MLT/chlorogenic acid were 1.60, 1.68, 2.02, 2.38, 2.32, 2.40, and 2.50, respectively. The results of desorption-regeneration cycles (seven times) by employing the MMIP showed the high stability of the resultant material. In conclusion, the MMIP combined with the magnetic separation showed a specific sorption behavior for MLT and suggested a simple, flexible, selective, and powerful analytical tool.Development of sensitive and selective analytical method for accurate diagnosis of Acinetobacter baumannii (Ab) bacteria in biological samples is a challenge. Herein, we developed an ingenious ratiometric fluorescent aptasensor for sensitive and selective detection of (Ab) bacteria based on fluorescence resonance energy transfer (FRET) between ortho-phenylenediamines carbon dot (o-CD), nitrogen-doped carbon nanodots (NCND) as donor's species and graphene oxide (GO) as acceptor. NCND that assembled onto the edge of graphene oxide (GO) exhibited quenched photoluminescence emission, and with the absorption of the modified o-CD with aptamer (o-CD-ssDNA) onto the graphene oxide surface the fluorescence of o-CD was efficiently quenched. The aptamer (ssDNA) as a biorecognition element is bound with A. baumannii specifically which releases the o-CD-ssDNA from GO and the recovery of the fluorescence signal of o-CD, while the fluorescence intensity of NCND only slightly altered and acted as the reference signal in ratiometric fluorescence assay. The fluorescence intensity ratio (I550 nm/I440nm) varied from 2.0 to 10.0 with the concentration of bacteria changing from 2.0 × 103 to 4.5 × 107 cfu/mL and the low detection limit of 3.0 × 102 cfu/mL (S/N = 3). The feasibility of the developed aptasensor for selective detection of A. baumannii in urine sample with satisfactory results was also demonstrated.Identifying the nature of gas-sensing material under the real-time operating condition is very critical for the research and development of gas sensors. In this work, we implement in situ Raman and XRD to investigate the gas-sensing nature of α-Fe2O3 sensing material, which derived from Fe-based metal-organic gel (MOG). The active mode of α-Fe2O3 as gas-sensing material originate from the thermally induced lattice expansion and the changes of surface oxygen vacancy of α-Fe2O3 could be reflected from the further monitored Raman scattering signals during acetone gas sensing. Meanwhile, the prepared α-Fe2O3 gas sensor exhibits excellent gas-sensing performance with high response value (Ra/Rg = 27), rapid response/recovery time (1 s/80 s) for 100 ppm acetone gas, and broad response range (5 - 900 ppm) at 183 °C. Strategies described herein could provide a promising approach to obtain gas-sensing materials with excellent performance and unveil the gas-sensing nature for other metal-oxide-based chemiresistors.Photonic crystal (PC)-based inverse opal (IO) arrays are one of the substrates for label-free sensing mechanism. IO-based materials with their advanced and ordered three-dimensional microporous structures have recently found attractive optical sensor and biological applications in the detection of biomolecules like proteins, DNA, viruses, etc. The unique optical and structural properties of IO materials can simplify the improvements in non-destructive optical study capabilities for point of care testing (POCT) used within a wide variety of biosensor research.  https://www.selleckchem.com/products/forskolin.html  In this review, which is an interdisciplinary investigation among nanotechnology, biology, chemistry and medical sciences, the recent fabrication methodologies and the main challenges regarding the application of (inverse opals) IOs in terms of their bio-sensing capability are summarized.The cotton plant is an essential crop cultivated globally for its fiber and seeds. In this study, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was used to study the spatial distribution patterns of lipids in cottonseeds. 448 lipid ions were identified by LC-MS/MS, and 24 of which were precisely visualized by using MALDI-MSI. The lipids, including phosphatidylcholines (PC), phosphatidylethanolamines (PE) and triacylglycerols (TG) showed heterogeneous distribution patterns within the cotyledonary and radicle tissues. Additionally, the roles these lipids played in the metabolic pathways were analyzed, and relationship of the spatial distribution of LPC (lysophosphatidylcholine) and corresponding PC was studied. The unique distribution patterns of these lipid metabolites revealed by MSI can provide new insights into areas relating to the spatial compartmentation of lipid metabolism in plants. We believe that the results of MSI, if combined with transcriptomics and proteomics, may offer significant help in genetic engineering work.