Silica gel/gold nanoparticles/(NS)2 ligand nanoporous platform-modified ionic liquid carbon paste electrode for potentiometric ultratrace assessment of Ag(I)

Abstract

A novel ionic liquid carbon paste electrode has been developed using sol-gel/Au nanoparticle (SGAN) involving (NS) 2 compound of N,N 0 -di-(cyclopentadienecarbaldehyde)-1,2-di(o-aminophenylthio) ethane (CCAE) as an appropriate neutral ion-carrier for ultrahigh-sensitive potentiometric determination of Ag(I). Colloidal gold nanoparticles (AuNPs) also well dispersed self-assembly into the 3-(mercaptopropyl)-trimethoxysilane (MPTS)-derived sol-gel network through Au-S covalent bond engendering continuous and super-conductive nanoporous three-dimensional array. The room-temperature ionic liquid, 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMIM.PF 6 ), was applied as a super-conductive pasting agent (binder). The SGAN/CCAE/IL-CPE exhibited a significantly enhanced sensitivity and preferential selectivity toward Ag(I) over a wide concentration range of 2.4 9 10 -9 to 2.2 9 10 -2 mol L -1 (R 2 = 0.9996) with a lower limit of detection of 7.9 9 10 -10 M and a Nernstian slope of 58.5 (±0.3) mV decade -1 . The electrode has a short response time of *5 s and long-time durability of about 2 months without any considerable divergence in potentials. Moreover, the potentiometric examinations could be carried out within the wide pH range of 3.5-9.5. Eventually, the practical utility of the proposed Ag(I)-sensor was evaluated by volumetric titration of AgNO 3 solution by sodium chloride and recovery of silver content in some real samples using flame atomic absorption spectroscopy as a confident reference.

Two Rival Newly Fabricated Potentiometric Sensors to Enhance Selectivity Toward Cu(II) Ions

“…Increasing the relative percent of L1 resulted in a notable deterioration in the detection limit, the slope, and the linear range of the electrode. This behavior is most probably due to some inhomogeneities and possible saturation of the paste [36]. Therefore, electrode #2 was adopted in further applications.…”

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“…Then the petridishes were visually inspected for observation (or not) of any growth inhibition halos. 18,19,20 The hydrogels equivalent to 4 mg of silver sulfadiazine was accurately weighed and added to 40 ml of pH 7.4 phosphate buffer as dissolution medium, maintained at 370. The electrode was immersed in the dissolution medium and the readings were noted directly from the potentiometer.…”