51. Effect of the Chain Length of a Modified Layer and Surface Roughness of an Electrode on Impedimetric Immunosensors.
- Author
-
Lin CH, Lin MJ, and Wu CC
- Subjects
- Carbon chemistry, Electrodes, Gold chemistry, Humans, Nanostructures chemistry, Particle Size, Surface Properties, 3-Mercaptopropionic Acid chemistry, Albuterol analysis, Immunoassay, Sulfuric Acids chemistry
- Abstract
An ultrasensitive label-free impedimetric immunosensor is constructed by modifying a 3-mercaptoproponic acid (MPA) monolayer on highly rough gold nanostructure (AuNS)-electrodeposited screen printed carbon electrodes (SPCEs) for the detection of small molecular weight drugs (SMWDs), such as salbutamol (SAL). The SPCEs preoxidized in a 0.1 M H
2 SO4 solution (called po-SPCEH2SO4 ) are electrodeposited with the AuNS to increase the roughness factor to 23.64 ± 1.76, larger than the AuNS/po-SPCENaOH or the AuNS/po-SPCEPBS . Furthermore, the MPA modified layer as a link for the anti-SAL immobilization to give the immunosensors an impedimetric signal-to-noise ratio larger than the 11-mercapto-undecanoic acid- and 16-mercaptohexadecanoic acid-modified layer, due to the lower interfacial impedance of the MPA monolayer. The MPA/AuNS/po-SPCEH2SO4 -based immunosensors have a wide linear range of 1 fg mL-1 to 1 ng mL-1 and a limit of detection of 0.6 fg mL-1 . Moreover, the immunosensors can practically quantify the SAL concentrations in 1000 times-diluted serum samples with good recovery.- Published
- 2017
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