Nanoengineered Electrochemical Sensor Based on Mesoporous Silica Thin-film Functionalized with Thiol-Terminated Monolayer
A mesoporous silica thin film was synthesized via a surfactant-templating process, where a silica sol gel is spin-coated onto the surface of a gold electrode. Upon removal of the surfactant, a film with 3D cubic pore structure and having a primary pore size of 77 was obtained. Thiol (-SH) functional groups were subsequently immobilized onto the mesoporous silica thin film through a self-assembly process. The thiol-immobilized mesoporous silica (SH-SAMMS) thin film was used as the electrode sensing layer for detection of lead(II) in aqueous solutions by employing a square wave adsorptive stripping voltammetry technique. The electrode modified with thin-film SH-SAMMS utilized the binding affinity of lead(II) to the thiol ligands to perform the preconcentration step under an open circuit, with no additional electrolytes, and at the pH in which the silica thin film was stable (pH 5-6). The voltammetric responses for lead(II) increased linearly with the preconcentration time from 1 to 30 minutes. The responses also increased linearly with lead(II) concentrations ranging from 250 to 5000 ppb after 5 minutes preconcentration and from 25-100 ppb after 30 minutes preconcentration.
- Research Organization:
- Pacific Northwest National Lab., Richland, WA (US), Environmental Molecular Sciences Laboratory (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 15006341
- Report Number(s):
- PNNL-SA-38216; ANALAO; 3278; TRN: US200412%%70
- Journal Information:
- Analyst, Vol. 128, Issue 7; Other Information: PBD: 1 Jul 2003; ISSN 0003-2654
- Country of Publication:
- United States
- Language:
- English
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