Electrocatalytic oxidation of NADH at gold nanoparticles loaded poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) film modified electrode and integration of alcohol dehydrogenase for alcohol sensing.
A new modified electrode is fabricated by dispersing gold nanoparticles onto the matrix of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid), PEDOT-PSS. The electrocatalytic activity of the PEDOT-PSS-Au(nano) electrode towards the oxidation of beta-nicotinamide adenine dinucleotide (NADH) is investigated. A substantial decrease in the overpotential (>0.7 V) has been observed for the oxidation of NADH at the PEDOT-PSS-Au(nano) electrode in comparison to the potential at PEDOT-PSS electrode. The Au nanoparticles dispersed in the PEDOT-PSS matrix prevents the fouling of electrode surface by the oxidation products of NADH and augments the oxidation of NADH at a less positive potential (+0.04V vs. SCE). The electrode shows high sensitivity to the electrocatalytic oxidation of NADH. Further, the presence of ascorbic acid and uric acid does not interfere during the detection of NADH. Important practical advantages such as stability of the electrode (retains approximately 95% of its original activity after 20 days), reproducibility of the measurements (R.S.D.: 2.8%; n=5), selectivity and wide linear dynamic range (1-80 microM; R(2)=0.996) are achieved at PEDOT-PSS-Au(nano) electrode. The ability of PEDOT-PSS-Au(nano) electrode to promote the electron transfer between NADH and the electrode makes us to fabricate a biocompatible dehydrogenase-based biosensor for the measurement of ethanol. The biosensor showed high sensitivity to ethanol with rapid detection, good reproducibility and excellent stability.
Manesh
K M
KM
Department of Chemistry Graduate School, Kyungpook National University, Daegu 702-701, South Korea.
Santhosh
P
P
Gopalan
A
A
Lee
K P
KP
D000426:Alcohol Dehydrogenase / Q000737:chemistry*; D000438:Alcohols / Q000032:analysis* / Q000737:chemistry; D001205:Ascorbic Acid / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D019086:Bridged Bicyclo Compounds, Heterocyclic; D002384:Catalysis; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D009243:NAD / Q000737:chemistry*; D010084:Oxidation-Reduction; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014527:Uric Acid / Q000737:chemistry
D000438:Alcohols; D019086:Bridged Bicyclo Compounds, Heterocyclic; D011108:Polymers; D011137:Polystyrenes; C121383:poly(3,4-ethylene dioxythiophene); D009243:NAD; D014527:Uric Acid; C003321:polystyrene sulfonic acid; D006046:Gold; D000426:Alcohol Dehydrogenase; D001205:Ascorbic Acid