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.

Quantitative information on the temperature dependence of BO2 emission band structure has been limited by the scarcity of experimentally validated spectral data. In this work, we present an experimental characterization of the visible A-X BO2 emission spectrum under well-controlled shock tube conditions across temperatures of 2200–3750 K. Spectrally resolved emission measurements reveal reproducible changes in the band structure with temperature. This work provides reference data for use in thermometry of boron combustion environments, while further guiding refinement of BO2 spectral modeling.

Flowers of Rosa damascena are used for food, medicine, and perfumery purposes. Thus, it is important to know their chemical profile. In this study, flowers of R. damascena at unopened and open stages were collected and analyzed after drying using a spectrophotometer and GC-MS. The results demonstrated that unopened flowers had the highest total phenols (0.5 mg g−1), total flavonoids (0.21 mg g−1), ascorbic acid (0.37 mg g−1), anthocyanins (0.19 mg g−1), and carotenoids (0.022 mg g−1). Similarly, unopened flowers contained more diverse compounds (48 compounds) than open flowers (38 compounds) regarding GC-MS analysis. Esters and alkenes were the most frequent chemical groups at both stages, but their numbers were the highest at the unopened stage. The most concentrated compounds at the unopened stage were octyl-β-D-glucopyranoside (19.76%) and phenylethyl alcohol (17.32%), but open flowers contained the maximum β-D-ribopyranoside, methyl (30.52%), and 4H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl (13.20%). The same compound exhibited different concentrations at both stages. Many detected compounds are known to have health effects, and most act as antimicrobial, anti-inflammatory, and antioxidant agents. Generally, diversity and concentration of the compounds in the flowers of R. damascena were influenced by the development stage, and the unopened stage was the richest in the compounds.

Green synthesis emerged as an effective approach for the eco-friendly synthesis of nanoparticles with improved biological applications. This study assesses the potential of root extract of Swertia cordata for the green synthesis of silver nanoparticles and examines their antimicrobial and antioxidant properties. Different analytical techniques such as UV-visible spectroscopy, Zeta potential, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM) analysis, were employed to characterize silver nanoparticles. The formation of silver nanoparticles was initially verified using UV-visible spectroscopy, which exhibited a characteristic absorption peak at 454 nm. XRD analysis revealed the face-centered cubic (FCC) crystalline structure. The zeta potential of −35 mV indicated the highest colloidal stability due to repulsion between the particles. The DLS confirms that the particle size distribution was between 80 and 120 nm. EDX analysis detected silver as the highest amount in the sample. The biosynthesized silver nanoparticles exhibit remarkable antibacterial activity against both Gram-negative bacteria and Gram-positive bacteria. The largest zone of inhibition was observed against Streptococcus pneumoniae (29 ± 1.5 mm) at a dose of 0.9 mg/mL. The synthesized silver nanoparticles also showed efficient and strong antifungal activity against two fungal strains, viz., Penicillium nutatum and Rhizopus stolonifera. The free radical scavenging activity of the synthesized silver nanoparticles was highest (69.5%) at 50 ppm of AgNPs concentration. The results confirm that silver nanoparticles synthesized from S. cordata root extract exhibited remarkable antimicrobial and antioxidant potential, making it therapeutic alternative for treating several diseases.

Herein, a simple and efficient method is described for the one-pot multicomponent click synthesis of pyrazole-based derivative (APC) using hydrazine hydrate, malononitrile, ethyl acetoacetate and 9-anthracenecarboxaldhyde. An efficient fluorescence quenching probe was then developed for the rapid determination of thiamin hydrochloride (THC) with high sensitivity and selectivity. Firstly, the fluorescence quenching experiment was carried out at different pH values, that are 1, 3, 5, 7, 9, 11 and 13. It was found that the fluorescence quenching efficiency response was maximum at neutral pH (pH = 7). The designed protocol afforded impressive fluorescence quenching results, offering a lower limit of detection of 2.55 μM, in the linear range of 1–25 μM. Additionally, the calculated value of the quenching constant or stern-Volmer constant was noted to be 1.823 × 104 M−1 or 0.01823 µM, depicting appreciable fluorescent quenching response. In order to get mechanistic insights of detection, the FT-IR, MS and 1H NMR titrations were conducted. The obtained results indicated that Photoinduced Electron Transfer (PET) phenomena was responsible for desired detection. Furthermore, the method was successfully applied for the quantification of Vitamin B1 in various kinds of real milk samples. The developed protocol afforded excellent recovery rates, ranging from 98.991 to 103.091%, for the real samples analysis test. Moreover, the selectivity test was also performed in order to check the applicability of the designed protocol toward targeted analyte. It has been depicted that the designed sensor offered noteworthy quenching efficiency, having a value of 92.8% for THC determination. Moreover, the greenness of the method has also been checked using AGREE software. The designed assay was quite simple, accurate, and less time-consuming with appreciable results that can be used for routine analysis and detection of thiamin hydrochloride.

In this study, a new method for preparing surface enhanced Raman scattering detection material based on membrane was proposed. First, Zeolitic imidazolate framework-67 was modified on a polypropylene membrane by in-situ growth. Subsequently, Ag nanoparticles were modified on the membrane by in-situ synthesis. After characterization by scanning electron microscopy, energy dispersive spectrometer, infrared spectrometer, x-ray diffractometer, x-ray photoelectron spectrometer and so on, it could be proved that Zeolitic imidazolate framework-67 and Ag nanoparticles were successfully modified on the surface of polypropylene membrane. The polypropylene membrane modified with Ag nanoparticles@Zeolitic imidazolate framework-67 prepared by the in-situ method has the advantages of good uniformity and stability of Zeolitic imidazolate framework-67 and Ag nanoparticles. Based on the polypropylene membrane modified with Ag nanoparticles@Zeolitic imidazolate framework-67, sample loading and surface enhanced Raman scattering detection of methylene blue could be completed within 3 min. As a result, the analysis time, on-line, real-time and practicality of surface enhanced Raman scattering detection was improved. In the analysis of real samples, compared with the polypropylene membrane modified with Ag nanoparticles@methyl-sulfur functionalized Zeolitic imidazolate framework-67 prepared by the covalent method, the polypropylene membrane modified with Ag nanoparticles@Zeolitic imidazolate framework-67 prepared by the in-situ method also showed better surface enhanced Raman scattering detection performance.

A highly selective optical sensor has been proposed for the detection of europium ion (Eu³ + ). The sensor was fabricated by embedding 2-amino-4-(3-nitrophenylazo) pyridine-3-ol (ANPAP) as the ionophore onto a clear agarose matrix. Spectrophotometric analysis of the interaction between ANPAP and various metal ions, such as Ca 2+ , Mn 2+ , Zn 2+ , Cu 2+ , Co 2+ , Ni 2+ , Pb 2+ , Fe 2+ , Cr³ + , Fe³ + , Sm³ + , Pr³ + , Eu³ + , Gd³ + , Er³ + , Lu³ + , La³ + , Sc³ + , Hg 2+ , Sr 2+ , Au³ + , and Al³ + in a buffered solution, demonstrated significantly higher stability for the Eu³ + ion complex. This was accompanied by a distinct change in color from yellow to blue, which emphasized the high selectivity of the ionophore for Eu³ + . A change in color from yellow to blue was observed when the sensing membrane was exposed to Eu³ + ions at pH 4.75. Factors such as ionophore concentration, pH, temperature, reaction time, and ionic strength were assessed. A strong linear correlation between Eu³ + ion concentration and the membrane absorbance at 444 nm was found within the range of 12.5–165 ng/mL, with an R 2 value of 0.995. No significant interference in determining Eu³ + ions was observed from the presence of potentially competing ions, even at concentrations 150 times high. The key characteristics of the optode developed, including reproducibility, regeneration capability, response time, and durability, are discussed in detail. The optode has been successfully used to detect Eu³ + ions accurately in spiked water samples from the environment.

Nanotechnology has emerged as a fast-expanding interdisciplinary field, with silver nanoparticles attracting substantial attention due to their broad applications in several fields. F. hispida bark extract was employed to synthesize and characterize silver nanoparticles as well as to assess their biological activity. Nanoparticles were fabricated using the acetone extract of F. hispida bark. UV-Vis spectroscopy, FTIR, XRD, HRTEM, FESEM, SAED, EDX, DLS and zeta potential studies were used to characterize the samples. Antioxidant activity was determined utilizing the DPPH and the reducing power protocols. Antimicrobial activity was assessed using the disk-diffusion and MIC determination methods. UV-Vis spectroscopy showed a characteristic surface plasmon resonance peak in the range of 420–450 nm and XRD confirms the crystalline, face-centered cubic structure with an average crystallite size of 24.42 ± 2.28 nm. FESEM/HRTEM tests confirmed spherical morphology with an average particle size of 21.05 ± 0.79 nm. FTIR spectra indicated that functional groups participate in the reduction and capping of silver nanoparticles. The SAED images showed a ring-like diffraction pattern, confirming crystallinity and EDX analysis identified silver as the main component. A negative zeta potential (−33.8 mV) was obtained, indicating the stability of nanoparticles. Synthesized nanoparticles showed concentration-dependent antioxidant activity, with an IC50 value of 18.09 µg/mL (DPPH assay) and an EC50 value of 244.4 µg/mL (reducing power assay). Moderate antimicrobial activity was observed, producing inhibition zones of approximately 7–12 nm and MIC values ranging from 15.625 to 62.5 µg/mL against the tested microorganisms. The produced silver nanoparticles exhibit potent antioxidant and antimicrobial activities, indicating their potential utility in antimicrobial and antioxidant-based materials; however, further studies, including cytotoxicity and biocompatibility evaluations, are required before biomedical applications can be considered.

Hydrogen-bonded organic frameworks (HOFs), a novel form of porous materials, have recently emerged as an ideal material for the construction of fluorescent sensors in recent years due to their mild preparation conditions, solution processability, and diverse structures. In this work, we synthesized a HOF material TCBP-HOF via hydrogen bonding self-assembly using 3, 3′, 5, 5′- tetra (4-carboxyphenyl) −1, 1′ - biphenyl (H4TCBP) as the raw material. The results showed that TCBP-HOF had good sensing performance for methylglyoxal (MGO), a 1, 2-dicarbonyl chemical widely distributed in thermally processed foods. Meanwhile, the fluorescence quenching mechanism of MGO on TCBP-HOF was mostly owing to the internal filtering effect (IFE) and photoinduced electron transfer (PET), which have been demonstrated through various methods. Finally, the sensor was used to detect MGO in genuine samples like milk and beer. This study is intended to broaden the application of HOF in fluorescence sensors.