Amperometric Assay of Sodium Dodecyl Sulfate Based on Anion Exchange Using PDDA as Active Acceptor
International Journal of Electrochemical Science
This study demonstrates a facile and effective strategy for amperometric assay of electrochemically inactive sodium dodecyl sulfate (SDS) based on different binding affinity of poly(diallyldimethylammonium chloride) (PDDA) toward electrochemically inactive SDS and active [Fe(CN) 6 ] 3-/4anions. To improve conductivity of the modified electrode nanomaterial, PDDA/GO/SWCNTs hybrid nanomaterial is first prepared and used as the artificial receptor to recognize the anions (i.e., [Fe(CN) 6 ] 3-/4and
... [Fe(CN) 6 ] 3-/4and SDS). The stronger binding affinity of the PDDA toward SDS than [Fe(CN) 6 ] 3-/4anions results in the decrease of the redox peaks current of surface modified PDDA and provides a quantitative signal readout for the SDS assay. Thereafter, an amperometric assay for SDS based on anion-exchange at [Fe(CN) 6 ] 3-/4-/PDDA/GO/SWCNTs modified glassy carbon electrode was developed. The ratio of the current decrease shows a linear relationship with SDS concentration range from 1.0 to 200 μM, and the limit of detection of SDS is 36.51 nM. And the results indicate that the study not only provides a simple and effective way to a polyanion of SDS assay, but also opens a new route to developing electrochemical methods for electrochemically inert contaminants by fully utilizing the anion-exchange principles.