Agarose-Based Fluorescent Waveguide with Embedded Silica Nanoparticle–Carbon Nanodot Hybrids for pH Sensing

The fabrication of a biodegradable and fluorescent cylindrical waveguide with doped hybrid nanoparticles (silica–carbon nanodots) is reported. hybrids were obtained by coupling amino-functionalized fumed silica the carboxylic acid surface groups amorphous carbon nanodots from thermolysis citric acid. present diameters lower than 10 nm, maximum fluorescence at 465 excitation-wavelength-dependent behavior. They occluded into an agarose matrix, providing low-cost easily scalable sensor capable detecting pH variations sensitivity 5.61 nm/(pH unit) when excited 403 nm UV light-emitting diode (LED).