Nanostructured poly(3,4-ethylenedioxythiophene)-metalloporphyrin films: improved catalytic detection of peroxynitrite.
We investigated in this paper the sensing performance of inherently conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), functionalized with hemin (iron protoporphyrin) as an electrocatalytic reporter. The sensing platform is prepared by electrodeposition of a composite film of hemin-PEDOT on a 30-microm diameter carbon fiber electrode (CFE). The polymerized films were characterized by field emission scanning electron microscopy (FESEM), which pointed to nanostructured films with tortuous pores. The electrocatalytic oxidation of peroxynitrite was characterized by cyclic voltammetry as well as other electrochemical methods. The catalytic current is proportional to the analyte's concentration. Optimized hemin-PEDOT modified CFEs were utilized for the first time to detect ONO2(-), with a response time down to 5 s and a limit of detection as low as 200 nM as evidenced by amperometry. Our hemin-PEDOT modified CFEs have a sensitivity of 13 nA/microM, ca.130 times higher than the bare CFE. More work is underway using other metalloporphyrins as electrocalalysts to improve the detection limit, the selectivity, and to further miniaturize these hemin-PEDOT modified electrodes.
Peteu
Serban
S
Department of Chemistry, Cleveland State University, 2121 Euclid Ave, Cleveland, OH 44115, USA.
Peiris
Pubudu
P
Gebremichael
Ermias
E
Bayachou
Mekki
M
D015374:Biosensing Techniques / Q000295:instrumentation*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D002384:Catalysis; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation; D030421:Peroxynitrous Acid / Q000032:analysis* / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011524:Protoporphyrins / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D019086:Bridged Bicyclo Compounds, Heterocyclic; D008567:Membranes, Artificial; D011108:Polymers; D011524:Protoporphyrins; C448299:iron protoporphyrin IX; C121383:poly(3,4-ethylene dioxythiophene); D030421:Peroxynitrous Acid