RESUMO
Phosgene is an important and widely used highly toxic chemical that poses a serious potential threat to public health and property if leaked or abused. Therefore, developing an efficient and convenient detection method for phosgene is of great significance. In this work, we synthesized a novel fluorescent probe, BCyP, based on benzohemicyanine for highly selective and sensitive detection of phosgene in both liquid and gas phases. The probe uses amino alcohol as a specific recognition group for phosgene and does not fluoresce due to the strong intramolecular charge transfer effect (ICT). However, in the presence of phosgene, the amino alcohol part in the probe can form oxazolidinone in situ with phosgene, reducing the ICT effect in the probe molecule and lighting fluorescence, thus realizing the selective phosgene detection. The probe exhibits good specificity towards phosgene, with significant fluorescence enhancement (approximately 400-fold), a remarkable Stokes shift (139 nm), a fast response speed (less than 17 s), and a low detection limit (0.12 ppm). Additionally, we prepared a phosgene detection paper strip loaded with the probe on filter paper and combined it with color recognition software on a smartphone to achieve visual detection of phosgene in the gas phase.
RESUMO
Leakage and misuse of phosgene, a common and highly hazardous industrial chemical, have always constituted a safety risk. Therefore, it is crucial to develop sensitive detection methods for gaseous phosgene. This work describes the design and development of a new fluorescent dye based on benzohemicyanine, as well as the synthesis of fluorescent probes for the sensitive detection of gaseous phosgene. Due to the excellent intramolecular charge transfer (ICT) effect from the strong electron-donating impact of the o-aminophenol group on benzo hemicyanine, the probe does not emit fluorescence. When the probe reacts with phosgene, the ICT effect is inhibited, and the result exhibits observable green fluorescence, thereby visualizing the response to phosgene. The probe offers exceptional sensitivity, a rapid response, and a low phosgene detection limit. In addition, we developed probe-loaded, portable test strips for the quick and sensitive detection of phosgene in the gas phase. Finally, the constructed probe-loaded test strips were utilized effectively to monitor the simulated phosgene leakage.
RESUMO
Cervical cancer is among the most prevalent forms of cancer worldwide. C-C chemokine receptor type 5 (CCR5) is hypothesized to be a key functional protein involved in tumorigenesis. However, the role of CCR5 in cervical cancer remains unclear. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to evaluate the mRNA and protein expression levels of CCR5 in human cervical carcinoma tissues. Furthermore, a small interfering RNA was employed to knockdown CCR5 in HeLa and C33A cells. MTT, colony formation and Transwell assays were performed to determine the effects of this knockdown on cell viability, proliferation and invasion. In addition, micro RNA (miR)-107 was identified as a potential candidate regulator of CCR5 using miR prediction algorithms, and the effects of miR-107 and its antisense miR on CCR5 mRNA expression were determined. The results of the present study indicated that CCR5 is overexpressed in human cervical cancer tissues compared with adjacent normal tissues, and its downregulation inhibits cervical cancer cell growth and proliferation. Furthermore, the downregulation of CCR5 appears to suppress cervical cancer cell invasion. Finally, the tumor suppressor miR-107 was able to directly target CCR5 and inhibit its expression. These results suggest that the upregulation of CCR5, which is inhibited by miR-107, may play a carcinogenic role in cervical cancer and could provide a novel therapeutic target in the future.
