Synthesis of fluorescent and water-soluble silicon nanoparticles with high pH response and its application to pH measurement and gastric parietal cell imaging
An extensive comprehension of biochemical activities happening in living systems is crucial for prior detection of diseases and characterization of suitable treatments. To understand the pathological/physiological conditions in living cells, the pH monitoring is an important tool. To date, the facile synthesis of nanosensors with strong fluorescence coupled with long emission wavelength and good photostability for pH monitoring is still remaining scanty. In this work, a new fluorescent silicon nanoparticles (Si NPs) allowing pH sensing was designed. The Si NPs were obtained from the mixture of 3-[2-(2-aminoethylamino) ethylamino] propyl-trimethoxysilane (AEEA) and 2-aminophenol in one-pot, and under excitation of 480 nm, they emitted yellow fluorescence at 560 nm. The Si NPs revealed excellent salt and temperature tolerant, robust photo stability, and high contrast fluorescence. Furthermore, the prepared Si NPs had been successfully applied to pH measurement in fruit juice samples and fluorescence imaging of gastric parietal cells in tissue section, providing a new approach for eosinophilic cell staining.