Highly sensitive antibiotic sensing based on optical weak value amplification: A case study of chloramphenicol.

The public health concern of antibiotic residues in animal-origin food has been a long-standing issue. In this work, we present a novel method for antibiotic detection, leveraging optical weak value amplification and harnessing an indirect competitive inhibition assay, which significantly boosts the system's sensitivity in identifying small molecule antibiotics. We chose chloramphenicol as a model compound and mixed it with chloramphenicol-bovine serum albumin conjugates to bind to the chloramphenicol antibody competitively.

Optical Label-Free Aptasensor Based on Weak Value Amplification for Real-Time and Ultrasensitive Detection of IgE.

Allergy is a prevalent disease, and the potential allergic population is expanding with industrialization and changes in people's living standards. Serum immunoglobulin E (IgE) level is one of the critical indicators for determining allergy. Here, we proposed a simple, real-time monitoring, low chip cost, label-free aptamer biosensing strategy based on weak value amplification (WVA) for the quantitative detection of IgE in serum samples, enabling early and accurate diagnosis of allergic or hypersensitive patients.

Realization of high-performance biosensor through sandwich analysis utilizing weak value amplification.

A label-free optical sandwich immunoassay sensor, utilizing weak value amplification and total internal reflection, was devised for real-time, high-sensitivity analysis and detection of low-concentration targets. 3D printed channels and sodium chloride solution were employed to ensure reproducibility, reliability, and stability of the measurements for calibration. The sandwich structure demonstrated enhanced responsiveness in the proposed optical biosensor through a comparative analysis of the direct assay and sandwich assay for detecting alpha-fetoprotein (AFP) at the same concentration.

Diisoprenyl Cyclohexene-Type Meroterpenoids with Cytotoxic Activity from a Mangrove Endophytic Fungus sp. GXNU-Y85.

Five new diisoprenyl cyclohexene-type meroterpenoids, aspergienynes J-N (-), along with three known analogues (-), were obtained from the mangrove endophytic fungal strain sp. GXNU-Y85. The chemical structures, including their absolute configurations, were established via spectroscopic data and comparison of experimental and calculated ECD spectra.

Cytotoxic metabolites from the mangrove endophytic fungus GXNU QG1a.

A new benzoquinone, guxiumasperone A (), and a new diisoprenyl-cyclohexene-type meroterpenoids, biscognienyne M (), along with four known diisoprenyl-cyclohexene analogues was isolated from the mangrove endophytic fungus QG1a. Their structures were determined by extensive spectral analysis of 1D and 2D NMR, HR-ESI- MS, and X-ray crystallography. Compound was deduced by a single-crystal X-ray diffraction analysis, and the absolute configuration of was further unequivocally elucidated by comparing the experimental electronic circular dichroism (ECD) data with calculated ECD spectra.

A new sulphur-containing metabolite from a mangrove endophytic fungus sp. GXNU-MA.

A new sulphur-containing metabolite, asperiguxidione A (), was isolated from a mangrove endophytic fungus sp. GXNU-MA, and four known alkaloids , were isolated together from this strain. Their structures were determined by the com-bination of 1D and 2D NMR spectroscopy, HR-ESI-MS, and ECD analysis.

Isolation and insecticidal activities of new cyclic peptides from mangrove endophytic fungus Aspergillus sp. GXNU-4QQY1a.

An investigation on bioactive metabolites from the mangrove endophytic fungus Aspergillus sp. GXNU-4QQY1a led to the isolation of two undescribed cyclic peptides, guaspertide A (1) and guaspertide B (2), together with six known compounds, 3-8. These structures and the new compounds' absolute configuration were determined by mass spectrometry analysis, nuclear magnetic resonance spectrum, electronic circular dichroism, and single-crystal X-ray diffraction.

Phytoconstituents of Selaginella effusa Alston and Their α-Glucosidase as well as Urease Inhibitory Activities.

Three new compounds (1-2, 14), as well as 22 known compounds (3-13, 15-25), were extracted for the first time from the Selaginella effusa Alston (S. effusa). For the unknown compounds, the planar configurations were determined via NMR and by high-resolution mass spectrometry, while their absolute configurations were determined by calculated electronic circular dichroism (ECD), and the configuration of the stereogenic center of biflavones 4-5 were established for the first time.