title: Strategically functionalized carbon nanotubes as the ultrasensitive electrochemical probe for picomolar detection of sildenafil citrate (Viagra).
abstract: The present work demonstrates the utility of the functionalized carbon nanotubes, poly(4-aminobenzene sulfonic acid) (PABS) grafted multiwalled carbon nanotubes, MWNT-g-PABS, as an electrode modifier towards achieving ultrasensitive detection of a model drug, sildenafil citrate (SC). PABS units in MWNT-g-PABS interact with SC, pre-concentrate and accumulate at the surface. The electron transduction from SC to electrode is augmented via MWNT-g-PABS. As a result, the MWNT-g-PABS modified electrode exhibited ultrasensitive (57.7 μA/nM) and selective detection of SC with a detection limit of 4.7 pM. The present work provides scope towards targeting ultrasensitivity for the detection of biomolecules/drug through rational design and incorporation of appropriate chemical components to carbon nanotubes.
authors.affiliation: Department of Chemistry Graduate School, Kyungpook National University, Daegu 702-701, South Korea.
authors.forename: Anantha Iyengar
authors.initials: AI
authors.lastname: Gopalan
authors.forename: Kwang Pill
authors.initials: KP
authors.lastname: Lee
authors.forename: Shanmugasundaram
authors.initials: S
authors.lastname: Komathi
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D055664:Electrochemical Techniques; D006801:Humans; D008297:Male; D008832:Microchemistry / Q000379:methods; D008855:Microscopy, Electron, Scanning; D055616:Microtechnology; D036103:Nanotechnology; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D058986:Phosphodiesterase 5 Inhibitors / Q000032:analysis; D010879:Piperazines / Q000032:analysis*; D011687:Purines / Q000032:analysis; D015203:Reproducibility of Results; D000068677:Sildenafil Citrate; D013425:Sulfanilic Acids / Q000737:chemistry; D013450:Sulfones / Q000032:analysis*
chemical_list: D037742:Nanotubes, Carbon; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D011687:Purines; D013425:Sulfanilic Acids; D013450:Sulfones; D000068677:Sildenafil Citrate