Design and synthesis of a combined meso-adsorbent/chemo-sensor for extraction and detection of silver ions

[Display omitted] •A simple, rapid and economic method for simultaneous detection and removal of silver ions was developed.•The detection strategy was based on complexation of silver ions using silica based AB90 chromogenic dye.•The limit of detection for silver ions was found to be 3.87 µg (Ag)/L.•The mesosensor could detect silver ions in 2.5 min with an UV–vis spectrophotometer.•The proposed colorimetric sensor is of high sensitive and selectivity in water and practical samples. We synthesized a new pH-dependent meso-captor/sensor for the visual monitoring and selective sequestering of Ag(I) ions from wastewater. The SBA-16 microspheres were successfully synthesized via a direct hydrothermal treatment through surfactant-assisted cooperative self-assembly. The meso-captor/sensor was designed via the direct immobilization of the chromogenic Acid Blue 90 (AB90) chelate into cubical large, open mesoporous SBA-16 carriers and investigate of its ability to detect and retain silver ions from aqueous solutions. Results show that the synthesized SBA-16 microspheres were retained after modification and the AB90 functional groups were immobilized hierarchically inside the mesopore channels. This was evidenced by the N2 adsorption, X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), High-Resolution Transmission Electron Microscope (HR-TEM), and elemental analyses. Batch adsorption experiments were carried out and the effects of various parameters on Ag(I) ions removal and detection were determined. The optimum adsorption/detection of Ag(I) ions were recorded at a pH of 6.2 within 30 min with color change from a brilliant blue to a pale blue-gray. The spectral response for [SBA-16@AB90 → Ag(I)] complex showed a maximum reflectance at λmax = 385 nm within 2.5 min response time (tR); the LOD was close to 3.87 µg/L while the LOQ approached 12.83 µg/L, this was attributed to the concentration range at which a linear signal has been observed against Ag(I) analyte concentration (i.e., 5 to 1000 µg/L) at pH 6.2 with standard deviation (SD) of 0.077 (RSD% = 9.5 at n = 8).