RESUMEN
The Pyrazoline derivatives display promising potential as sensitive and selective chemosensors for detecting Cu2+ ions. It has undergone screening for its sensing behavior with various metals using absorption, emission spectroscopic techniques. Their unique structure incorporates both donating and accepting sites, characterized by delocalized orbitals. These derivatives exhibit notable chromogenic and fluorogenic capabilities facilitated by intramolecular charge transfer. The sensors based on pyrazoline demonstrate exceptional selectivity, low detection limits, and precise detection of metal ions, particularly Cu2+. This review offers a comprehensive summary of recent discoveries concerning as pyrazoline-based "On-Off" chemosensors. The discussion places emphasis on exploring the design and photophysical properties of these chemosensors, with the primary objective of detecting Cu2+ metal ions. The unique features of pyrazoline derivatives make them promising candidates for practical applications in environmental and biological monitoring, showcasing their potential significance in advancing sensing technologies.
RESUMEN
The chalcone compound DHPO was synthesized through a chemical reaction between 1-(2-hydroxyphenyl)-ethanone and 3,4-dimethoxy benzaldehyde under ultrasound irradiation. The interaction between the DHPO compound and several metal ions was studied using fluorescence behavior, revealing that the chalcone function as a "turn on and turn off" switch fluorescent sensor, for selectively and sensitively detecting Fe3+ ions. The process of fluorescence quenching and complexation of DHPO with Fe3+ ion was further studied using methods such as Benesi-Hildebrand, Stern-Volmer plot, and job plot.
RESUMEN
BACKGROUND: Heavy metals and antimicrobials co-exist in many environmental settings. The co-exposure of heavy metals and antimicrobials can drive emergence of antimicrobial resistant (AMR) Enterobacteriaceae. We hypothesized that co-exposure to heavy metals and a low concentration of antibiotic might alter antimicrobial susceptibility patterns, which facilitate emergence of AMR Staphylococcus aureus. METHODS: The growth kinetics of antimicrobial susceptible S. aureus was carried out in the presence of chromium or cadmium salt and a low concentration of antibiotics. Subsequently, the antimicrobial susceptibility pattern was determined by the Kirby-Bauer disc diffusion method. Moreover, the mRNA copy number was determined by reverse transcription polymerase chain reaction. RESULTS: The antimicrobial susceptibility profile revealed that the zone of inhibition (ZOI) for ampicillin, amoxicillin, ciprofloxacin and doxycycline was significantly decreased in chromium pre-exposed S. aureus compared to unexposed bacteria, whereas cadmium pre-exposed bacteria only showed significant decreased in ZOI for amoxicillin. Moreover, the MIC of amoxicillin for S. aureus was increased by 8-fold in chromium and 32-fold in cadmium when bacteria were co-exposed with low concentrations of amoxicillin. The mRNA expression of femX, mepA and norA also significantly increased in S. aureus after exposure to chromium and a low concentration of amoxicillin. CONCLUSION: Cultivation of S. aureus at the minimum levels of chromium or cadmium and a low concentration of amoxicillin increased the inhibitory concentration of amoxicillin through inducing bacterial efflux pumps and antibiotic resistant genes. However, it is warranted to assess the whole transcriptome to find out all responsible factors behind this de novo amoxicillin resistant S. aureus.
