Quenching mechanism of PEG emission by pyrimidines and their detections using PEG as fluorescent sensor

Phase Transition and Fluorescence Emission of Multiresponsive Poly(ethylene glycol-co-siloxane) and Its Application for Uric Acid Detection

“…It has been well accepted that this type of fluorescence emission, including the emission intensity and the wavelength, is dependent on the concentration of the nonconventional fluorescent polymer. − , The dependence of PEG-Si emission on its concentration was then tested by taking P6 as an example. First, a set of P6 solutions at different concentrations (10–150 mg/mL) was first prepared with their pH adjusted at 10.…”

“…However, for the same measurement of cluster size for the samples at higher [NaCl] (>150 mmol/L), a significant increase in the cluster size was detected: about 10 and 13.5 nm with the [NaCl] at 200 and 300 mmol/L, respectively, and the size up-rushed to 295 nm with the [NaCl] at 400 mmol/L (Figure S13). It is well-known that the emission of the CTE type of unconventional polymers is closely controlled by the size of their cluster and the size distribution. − , These results mean that, in the presence of a low amount of NaCl, the clustering of P6 was promoted to a limited extent, yielding a slight increase in cluster size, for which the optional excitation light (275 nm) for the pure P6 solution (free of NaCl) is still highly effective to excite the clusters, leading to enhanced emission for [NaCl] up to 150 mmol/L. However, for the samples with [NaCl] above that concentration, the cluster size was increased to a far larger size than that at low [NaCl], e.g., 150 mmol or lower.…”

“…It is well-known that the emission of the CTE type of unconventional polymers is closely controlled by the size of their cluster and the size distribution. [18][19][20][21][22][23][24][25]28 These results mean that, in the presence of a low amount of NaCl, the clustering of P6 was promoted to a limited extent, yielding a slight increase in cluster size, for which the optional excitation light (275 nm) for the pure P6 solution (free of NaCl) is still highly effective to excite the clusters, leading to enhanced emission for [NaCl] up to 150 mmol/L. However, for the samples with [NaCl] above that concentration, the cluster size was increased to a far larger size than that at low [NaCl], e.g., 150 mmol or lower.…”

“…Based on the fact that their clustering is due to heteroatom clustering, they are in general more hydrophilic and more biocompatible, in comparison to conventional fluorescent polymers consisting of a large conjugation structure and classical chromophores. They have become one of the most exciting areas in fluorescent polymer research. − A vast number of CTE polymers, including polyurea, polyethylene glycol, , polyamide, and amide salt, have been studied and potential applications explored. − N -Isopropylacrylamide (NIPAM)-based polymers, often referring to a series of widely studied temperature-responsive polymers, , are also reported to have CTE properties . However, they are widely known to have response hysteresis, strong protein adsorption due to strong hydrogen bonding, and toxicity after hydrolysis because of organic amine release .…”