Benefit from the additional correction of the output signal in dual-mode detection, traditional dual signal readout strategies are performed by constructing the ratiometric fluorescent probe through excitation energy transfer (EET) or fluorescence resonance energy transfer (FRET). To avoid the complicated modification process and obtain the results rapidly, a simple dual-mode sensing strategy based on the electronic effects of p-nitrophenol (PNP) is described to monitor the activities of alkaline phosphatase (ALP). In the sensing platform, p-nitrophenylphosphate was used as a substrate to produce the PNP using ALP as the catalyst. Due to the PNP possesses negative effect of induction and conjugation, photoinduced electron transfer and hyperchromic effect have been achieved between PNP and polyethyleneimine-protected copper nanoclusters (PEI-Cu NCs), which caused the changes of the fluorescence intensity and UV–visible absorption. The dual-mode signal sensing system showed the satisfactory linear results of ALP from 1 to 100 U/L for fluorescent sensing strategy and 1–70 U/L for the absorption method with a competitive LOD of 0.27 and 0.87 U/L (signal-to-noise ratio of 3). This strategy detected biological ALP in human serum and bio-imaging of endogenous ALP in A549 cells successfully, which verifies a certain potential of the strategy for the practical applications.
Cai-yun LIU,Lu-lu WU,Shu-yue FAN,Yong-sheng TAO,Yun-kui LI
The impact of cyclodextrins (CDs) on wine quality and stability has been seldomly reported. This study systematically assessed the protective effect of post-fermentation addition of CDs on color stability of red wine from the viewpoints of color characteristics, copigmentation and phenolic profiles. The grey relational analysis (GRA) and principal component analysis (PCA) were employed to dissect the key effective determinants related to color quality. The addition of CDs induced a significant hyperchromic effect of 8.19%-25.40%, significant bathochromic effect and enhancement of the color intensity. Furthermore, the evolution of anthocyanin form and the content of monomeric anthocyanins revealed that β -CD is a superior favorable cofactor during wine aging, but for the long-term aging, 2-HP- β -CD and 2-HP- γ -CD are more beneficial in promoting the formation of polymerized anthocyanins and the color stability. This work provides an important reference for the use of CDs to enhance color quality and stability of red wines.
危险品化学品经营许可证（带存储）