Ultra-large Stokes-shifted NIR fluorescent probe for diagnosis of APAP-induced liver injury and its applications in food and bioimaging.

High-throughput identification of geographical origins of rubies using hyperspectral visible and fluorescence spectroscopy.

Multimodal anticancer potential of newly synthesized palladium(II), platinum(II), and gold(III) complexes with 2-(Thiazol-2-yl)pyridine-4,5-dicarboxylate dimethyl ester.

Multiphoton imaging coupled with steady-state and time-resolved fluorescence spectroscopy reveals protein-bound FAD in femtosecond-laser-injured regenerating muscle.

Macro- to molecular-scale insights into organic carbon redistribution during thermal hydrolysis-anaerobic digestion of waste activated sludge.

Viscosity-sensitive NIR probe for detecting cellular state transitions in Normal, Cancer and apoptotic cells.

This study demonstrates the suitability of a handheld fluorescence device for the detection of cold chain disruptions (CCDs) of modified-atmosphere packaged minced pork through the package or with unpacked samples. Fluorescence spectra of minced pork stored at a constant temperature of 2°C were highly correlated with the storage time after processing of the meat. Partial least squares regression (PLSR) models for spectra recorded through the package or for unpacked samples yielded cross-validated R2CV=0.90 or 0.95, respectively. Validation with independent samples investigated under controlled conditions resulted in R2Pred=0.83 for measurements through the package and 0.88 for measurements of unpacked samples. Unlike the controls, minced pork, which underwent a CCD at 14°C on storage day 2, was systematically predicted older than its actual storage time depending on the duration of the disruption: 1.1-1.7 d older after a 6-h disruption and with 2.5-3.5 d significantly older after a 12-h disruption. In contrast, CCD-dependent changes of total viable counts (TVC) only appeared on tendency after a 12-h CCD and PLSR predictions of TVC performed inadequately. The storage-time effect detected by fluorescence spectroscopy was apparent already one day after the disruption. The results indicate that fluorescence spectra monitor an ageing process of meat, which is accelerated by a temporarily elevated storage temperature. The comparison of predicted and actual storage time could be useful for a rapid, non-invasive detection of cold chain disruptions and for an assessment of time and temperature effects on the shelf life.

Antimicrobial peptides (AMPs) represent a current strategy to develop new antibiotics against multi-resistant pathogens. The potential antibiotic activity of AMPs is related to their amphipathic properties and the presence of positively charged residues, which may interact with the negatively charged bacterial membranes. In contrast, they exhibit lower interaction with the eukaryotic, neutrally charged membranes. This is the primary reason AMPs can distinguish between eukaryotic and prokaryotic membranes. AMPs are usually modified or designed de novo, and their properties can be changed by inserting specific amino acid residues into their sequence. To assist in the rational design of AMPs, it is helpful to explore the biophysical changes they may induce in target cell membranes. Therefore, bacterial and eukaryotic model lipid membranes have been extensively used for this purpose. Parameters such as selective binding, lipid membrane interactions, membrane packing, permeability, hydration, and restructuring facilitate the exploration of peptide regions of interest. These parameters can be studied using various physicochemical techniques, including differential scanning calorimetry, X-ray diffraction, nuclear magnetic resonance, and fluorescence spectroscopy. This review aims to provide a practical guide to the main biophysical techniques used to explore the potential antibiotic activity of AMPs using model membranes, and to examine lipid-peptide interactions in order to define the mechanisms of action of these antimicrobial peptides. These techniques determine whether the peptide interacts specifically with bacterial membranes, the preferred bacterial target of a given AMP, the binding affinities of AMPs, potential pore formation and its geometry, and the impact of these interactions on both bacterial and eukaryotic membranes.

Classification of DNA secondary structures by combining multiple spectral techniques with machine learning.

The detection of shrimp allergenicity in food based on recombinant tropomyosin by LFIA method.

A novel amide-quinoline salt-based mitochondrial-targeted fluorescent probe for detecting pH in cells and water samples.

Front-face synchronous fluorescence spectroscopy coupled with PLSR for rapid quantitative analysis of Chinese five-spice powder composition.

Thermal degradation kinetics of curcumin in dry-heated turmeric powder studied by front-face synchronous fluorescence spectroscopy.

The effect of cation substitutions in the scheelite-type framework is investigated to understand the ordering of M+/Pr3+ cations and vacancies in the structure. The cation deficient M1/8Pr5/8□1/4MoO4 (M = Li, Na, K) phases were synthesized using solid state reactions. The K:Pr ratio in the K1/8Pr5/8MoO4 sample was determined by inductively coupled plasma mass spectroscopy, inductively coupled plasma optical emission spectrometry and total reflection X-ray fluorescence spectroscopy. The local element distributions in K1/8Pr5/8□1/4MoO4 were determined by energy-dispersive X-ray spectrometry. The incommensurately modulated crystal structures of the scheelite-based M1/8Pr5/8MoO4 (M = Li, Na, K) phases were refined from synchrotron powder X-ray diffraction data. The analysis revealed that cation ordering in the M1/8Pr5/8MoO4 (M = Li, Na) structures is incomplete and is more accurately described by continuous, rather than discontinuous (step-like), occupational modulation functions. The occupancy modulation waves for Li/Na and Pr atoms demonstrate an antiphase relation. Compared with M = Li, Na, the order of K and Pr cations in the A position in the K1/8Pr5/8MoO4 structure is best approximated by crenel functions. Refining the coordinates and lengths of three atomic domains yields the composition of K0.145Pr0.618MoO4. In all cases, the modulation arises from ordering of M/Pr cations and cation vacancies at the A-sublattice of the parent scheelite ABO4 structure. The distortion of PrO8 and MO8 polyhedra is practically independent of the radius of the M+ cations. The refinements of the M1/8Pr5/8MoO4 (M = Li, Na, K) structures reveal that MoO42- tetrahedra in these scheelite-type compounds demonstrate a flexible geometry. Both Mo-O bond distances and O-Mo-O bond angles vary significantly with changing the population of the A site by cations with different sizes.

Insights into impact of tire additives on activated sludge systems: Treatment performance, extracellular polymeric substances, and microbial community.

Determination of selenium at ultra-trace level in foods using energy-dispersive X-ray fluorescence supported by soft-template mesoporous carbons modified with thiol groups by impregnation using PETMP.

Development of flame frequency stabilized-continuous wave laser excited atomic fluorescence spectrometric (flame-cw-LEAFS) technique and its applications for ultra-trace level determination of rubidium in spodumene.

Polymyxins B and E (colistin) were historically the last-resort antibiotics for treating infections caused by multidrug-resistant Gram-negative bacteria. However, their narrow therapeutic windows and significant nephrotoxicity necessitate rapid and precise detection methods. In this study, we employed a mixture of polymyxins B and E as targets to isolate DNA aptamers via the capture-SELEX method. Sequence analysis revealed two primary families, both characterized by three-way junction structures. The first family, represented by PM-2, exhibits comparable low-micromolar affinity for both polymyxins B and E and features a loopless three-way junction. In contrast, the PM-3 family demonstrates higher potency and selectivity, binding polymyxin B with a dissociation constant of 440 nM, approximately 10-fold stronger than its binding to polymyxin E, as determined by isothermal titration calorimetry. Binding assays under varying ionic strengths showed that affinity decreased with increasing salt concentration, suggesting that electrostatic interactions drive molecular recognition. Furthermore, thioflavin T fluorescence spectroscopy confirmed target-specific binding. Leveraging these distinct binding profiles, we developed a sensor array capable of discriminating between these two closely related antibiotics using a principal component analysis. These aptamers provide a robust foundation for the analytical detection and monitoring of polymyxin antibiotics in clinical settings.

The effect of β-cyclodextrin (β-CD) coexistence and encapsulation on the interaction between butylated hydroxyanisole (BHA) and bovine serum albumin (BSA). The results of various spectral analyses, including fluorescence spectroscopy, three-dimensional (3D) fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and circular dichroism spectroscopy (CD), revealed that β-CD suppresses BHA-BSA binding through dual mechanisms, thereby mitigating BHA-induced conformational alterations in BSA. Specifically, upon formation of the BHA/β-CD inclusion complex, the binding affinity of BHA to BSA was significantly weakened, with the binding constant decreasing from 6.10 × 103 M−1 to 5.36 × 102 M−1. The thermodynamic analysis indicated that BHA to BSA binding is primarily driven by hydrophobic interactions. However, β-CD shifts this interaction to is a weakly entropy-driven or enthalpy-entropy compensation mechanism. Moreover, the coexistence and encapsulation of β-CD did not significantly affect BHA’s antioxidant capacity and esterase-like activity. The β-CD encapsulation protects BSA’s native conformation.

A series of heptagon-embedded multiple helicenes was synthesized in which the heptagon subunit was fused to the π-framework through Knoevenagel condensation reactions. By controlling the conditions of the cyclodehydrogenation (Scholl) reactions, different fused chiral and twisted PAHs were accessible. The optical and electronic properties of all products were investigated by UV-vis, fluorescence spectroscopy, and cyclic voltammetry. One member of the series displays an unusual anti-Kasha-like fluorescence emission. In addition, all the enantiopure [6]helicenes were separated by chiral HPLC and characterized by circular dichroism spectroscopy.