An integrated electrochemical fructose biosensor based on tetrathiafulvalene-modified self-assembled monolayers on gold electrodes.
An integrated amperometric fructose biosensor based on a gold electrode (AuE) modified with a self-assembled monolayer (SAM) of 3-mercaptopropionic acid (MPA) on which fructose dehydrogenase (FDH) and the mediator tetrathiafulvalene (TTF) are co-immobilized by cross-linking with glutaraldehyde is reported. Variables concerning the behavior of the biosensor were optimized by taking the slope value obtained for the fructose calibration plot in the 0.1-1.0 mM concentration range as a criterion of selection. At an applied potential of +0.20 V, a good repeatability of such slope values (RSD=6.7%, n=10) was obtained with no need to apply a cleaning or pretreatment procedure to the modified electrode. Moreover, results from five different TTF-FDH-MPA-AuEs yielded a RSD of 5.8%. The useful lifetime of one single biosensor was approximately 30 days, exhibiting a 93% of the original response on the 33rd day. A linear calibration graph was obtained for fructose over the 1.0 x 10(-5)-1.0 x 10(-3) M range, with a limit of detection of 2.4 x 10(-6) M. The effect of potential interferents was evaluated. The TTF-FDH-MPA-AuE also performed well in the flow-injection mode. The biosensor was used for the determination of fructose in real samples, and the results compared with those provided by using a commercial enzyme test kit.
Campuzano
Susana
S
Dpto. Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, 28040, Madrid, Spain.
Gálvez
Rocío
R
Pedrero
María
M
Manuel de Villena
F Javier
FJ
Pingarrón
José M
JM
D015097:3-Mercaptopropionic Acid; D015374:Biosensing Techniques; D004563:Electrochemistry; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D005632:Fructose / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D006571:Heterocyclic Compounds; D006722:Honey / Q000032:analysis; D031989:Pyrus / Q000737:chemistry
D004800:Enzymes, Immobilized; D006571:Heterocyclic Compounds; D005632:Fructose; D006046:Gold; D015097:3-Mercaptopropionic Acid; C063887:tetrathiafulvalene