Bio-inspired chitosan/polydopamine-nanoparticle based sorbent bead: A versatile platform for separation and HPLC analysis of tetracycline antibiotics from various sample matrix.

This study introduces an innovative bio-based sorbent bead crafted by integrating chitosan (CS) biopolymers, Fe(NO3)3 and polydopamine nanoparticles (PDA NPs) via glutaraldehyde crosslinking. The primary focus of this study was the concurrent separation of diverse tetracycline antibiotics (TCs), followed by rigorous reversed-phase liquid chromatography analysis. The fabricated CS/Fe@PDA sorbent beads were comprehensively characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy, revealing a surface rich in active carbon (C), nitrogen (N), and oxygen (O) moieties.

Colorimetric and Smartphone-Based Dual-Mode Rapid Detection of Congo Red Using Iron Oxide Quantum Dots.

Congo red is toxic to humans and the environment and persists in the environment for long periods. Therefore, developing a rapid detection method for Congo red is crucial. In this study, iron oxide quantum dots (IOQDs) were synthesized and employed for dual-mode detection (colorimetric and smartphone-based) of Congo red in real samples.

Fluorescence and Colorimetric Dual-Readout Detection of Tetracycline Using Leucine-Conjugated Iron Oxide Quantum Dots.

This study developed a dual-readout system utilizing fluorescence and colorimetry based on iron oxide quantum dots (IO-QDs) for detecting tetracycline (TCy). IO-QDs were synthesized within 6 h using L-leucine as a surface modifier, achieving a more efficient route. Upon interaction with TCy, IO-QDs exhibited a significant decrease in fluorescence response and observable color changes, while fluorescence lifetime remained consistent regardless of TCy presence.

Steric and electronic influence on Cu-Cu short contacts in β-thioketiminato tricopper(I) clusters.

A series of β-thioketiminate copper(I) complex trimers [LCu] were synthesized by modifying the ligand framework with electron-withdrawing groups (F and Cl) or electron-donating groups (Pr and Me) at the -aryl ring as well as with CF groups on the chelating backbone. This ligand modification significantly impacts the enhancement of Cu⋯Cu short contacts, which can be rationalized by using steric and electronic factors of the chelated ligand. We observed that this intramolecular cuprophilicity among [LCu] complexes is primarily governed by the size of -aryl -substituents.

Understanding Antibiotic Detection with Fluorescence Quantum Dots: A Review.

The utilization of fluorescent quantum dots (FL QDs) has gained significant traction in the realm of antibiotic detection, owing to their exceptional FL properties and versatility. Various types of QDs have been tailored to exhibit superior FL characteristics, employing diverse capping agents such as metals, surfactants, polymers, and biomass to protect and stabilize their surfaces. In their evolution, FL QDs have demonstrated both "turn-off" and "turn-on" mechanisms in response to the presence of analytes, offering promising avenues for biosensing applications.

Turn-off/turn-on biosensing of tetracycline and ciprofloxacin antibiotics using fluorescent iron oxide quantum dots.

A fluorescence probe based on iron oxide quantum dots (IO-QDs) was synthesized using the hydrothermal method for the determination of tetracycline (TCy) and ciprofloxacin (CPx) in aqueous solution. The IO-QDs were characterized using high-resolution transmission electron microscopy (HR-TEM), powder X-ray diffraction (P-XRD), vibrating sample magnetometry (VSM), and Fourier-transform infrared spectroscopy (FTIR). The as-prepared IO-QDs are fluorescent, stable, and with a fluorescence quantum yield (QY) of 9.

Polyvinylpyrrolidone-passivated fluorescent iron oxide quantum dots for turn-off detection of tetracycline in biological fluids.

Tetracycline is an antibiotic that has been prescribed for COVID-19 treatment, raising concerns about antibiotic resistance after long-term use. This study reported fluorescent polyvinylpyrrolidone-passivated iron oxide quantum dots (IO QDs) for detecting tetracycline in biological fluids for the first time. The as-prepared IO QDs have an average size of 2.

Denticity governs the formation of β-thioketiminato tri-copper(I) and mono-copper(I) complexes.

Two classes of β-thioketiminate ligands, SN chelators (HL1 and HL2) and SNN chelators (HL3 and HL4), were prepared to understand their coordination behavior in copper(I) complex formation. The formation of these copper(I) complexes bearing β-thioketiminate ligands and their corresponding adducts toward isocyanide, PPh, and CO was investigated to address two important issues. First, whether the denticity governs the copper(I) thiolate species formation between SN chelators and SNN chelators.

Glutamic acid-capped iron oxide quantum dots as fluorescent nanoprobe for tetracycline in urine.

The fabrication of iron oxide quantum dots (IO-QDs) modified with glutamic acid (Glu) under controllable conditions is reported. The IO-QDs have been characterized by transmission electron microscopy, spectrofluorometry, powder X-ray diffraction, vibrating sample magnetometry, UV-Vis spectroscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The IO-QDs exhibited good stability towards irradiation, temperature elevations, and ionic strength, and the quantum yield (QY) of IO-QDs was calculated to be 11.

Rambutan seed waste-derived nitrogen-doped carbon dots with l-aspartic acid for the sensing of Congo red dye.

In this study, new nitrogen-doped carbon dots (N-CDs) were prepared by utilizing rambutan seed waste and l-aspartic acid as dual precursors (carbon and nitrogen sources) through a hydrothermal treatment method. The N-CDs showed blue emission in solution under UV light irradiation. Their optical and physicochemical properties were examined UV-vis, TEM, FTIR spectroscopy, SEM, DSC, DTA, TGA, XRD, XPS, Raman spectroscopy, and zeta potential analyses.

Enhanced fluorescent iron oxide quantum dots for rapid and interference free recognizing lysine in dairy products.

In this work, a simple, easy and selective method for sensing lysine in an acidic medium was developed based on fluorescent iron oxide quantum dots (IO QDs). IO QDs using the hydrothermal method were prepared with different conditions (concentration of NPs, amount of citric acid, heating time, heating temperature, and total volume in the hydrothermal reactor) where iron oxide nanoparticles (IO NPs) were used as the starting materials. TEM, FTIR, UV-Vis Spectrometry, fluorescence spectrometry, Powder XRD, VSM were used to characterize the as-prepared IO QDs.

Plant Part-Derived Carbon Dots for Biosensing.

Carbon dots (CDs) are a new cluster of carbon atoms with particle size less than 10 nm. CDs also exhibit interesting fluorescence (FL) properties. CDs are attractive because of their fascinating characteristics including low toxicity, good water solubility, and tremendous biocompatibility.