Smart glass substrate as colorimetric chemosensor for highly selective detection of silver ion

This paper reports the fabrication of new chemosensor based on the aminoacridine immobilized glass substrate. The fabricated chemosensor was highly selective and sensitive for the detection of Ag+. Although each of the chemosensing molecules on the glass substrate does not have the specific ligand, the molecules got specific selectivity for Ag+ owing to the suitable distance between them. Ag+ formed the chelating complex with the chemosensing molecules as not intra- but inter-molecular structure. After the formation of the chelating complex, surface properties, such as the morphology and the wettability, were changed owing to the bent amidine groups of the chemosensing molecules on the glass substrate. The chemical structure and the surface properties of the chemosensor-Ag+ were analyzed using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and contact angle goniometer. Combining these techniques enables discussion of mechanism of the chemosensor-Ag+ complex. In addition, the prepared chemosensor showed a selective absorbance change only with Ag+, indicating that the sensing system described herein exhibits high selectivity for Ag+ detection against other metal ions.