| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1165546 | Analytica Chimica Acta | 2013 | 6 Pages |
Pentacyanoferrate-bound poly(1-vinylimidazole) (PVI[Fe(CN)5]) was selected as a mediator for amperometric creatinine determination based on the reductive H2O2 detection. Creatinine amidohydrolase (CNH), creatine amidohydrolase (CRH), sarcosine oxidase (SOD), peroxidase (POD), and PVI[Fe(CN)5] were crosslinked with poly(ethylene glycol) diglycidyl ether (PEGDGE) on a glassy carbon (GC) electrode for a creatinine biosensor fabrication. Reduction current was monitored at −0.1 V in the presence of creatinine and O2. It is revealed that PVI[Fe(CN)5] is suitable as a mediator for a bioelectrocatalytic reaction of POD, since PVI[Fe(CN)5] neither reacts with reactants nor works as an electron acceptor of SOD. The amounts of PVI[Fe(CN)5], PEGDGE, and enzymes were optimized toward creatinine detection. Nafion as a protecting film successfully prevented the enzyme layer from interferences. The detection limit and linear range in creatinine determination were 12 μM and 12–500 μM (R2 = 0.993), respectively, and the sensitivity was 11 mA cm−2 M−1, which is applicable for urine creatinine tests. The results of the creatinine determination for four urine samples measured with this proposed method were compared with Jaffe method, and a good correlation was obtained between the results.
Graphical abstractThe detection mechanism of creatinine biosensor. CNH: creatinine amidohydrolase, CRH: creatine amidohydrolase, SOD: sarcosine oxidase, POD: peroxidase. The hollow arrows and the cross symbol indicate the extremely low reactivity of PVI[Fe(CN)5] against SOD.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► PVI[Fe(CN)5] has a low reactivity against sarcosine oxidase (SOD). ► PVI[Fe(CN)5] is suitable as a mediator for the SOD/peroxidase sensing system. ► The catalytic effects of mediator are related to the hydrophilic/phobic properties. ► The proposed biosensing method is applicable for urine creatinine determination.
