Photoelectrochemical glucose biosensor based on a dehydrogenase enzyme and NAD+/NADH redox couple using a quantum dot modified pencil graphite electrode

RSC Advances ◽  
2016 ◽  
Vol 6 (24) ◽  
pp. 20058-20066 ◽  
Author(s):  
Bensu Ertek ◽  
Cahit Akgül ◽  
Yusuf Dilgin

A simple, disposable and economical modified electrode was prepared by electrodeposition of hybrid quantum dots onto a pencil graphite electrode surface and immobilization of glucose dehydrogenase onto the quantum dot modified electrode.

2019 ◽  
Vol 31 (10) ◽  
pp. 2185-2190
Author(s):  
G. Sivasankari ◽  
K. Sivasankari ◽  
T. Nalini ◽  
P. Padmapriya ◽  
M. Nadhiya

An electrochemical sensor has been developed using methylene blue (MB) unctionalized graphite for the selective determination of dopamine in the presence of ascorbic acid. The immobilization of methylene blue on graphite was done by carbodiimide coupling method. The methylene blue functionalized graphite was characterized by SEM, FTIR spectroscopy and UV-visible spectroscopy. The immobilization of methylene blue functionalized graphite (MB-G) on the electrode surface was made by drop casting a small volume of MB-G dispersed methanol solution on the electrode surface. About 5 L of 0.5 % Nafion solution was also dropcasted for the stability and selectivity. The MB-G modified electrode was characterized by cyclic voltammetry. The modified electrode promotes the electrocatalytic oxidation of dopamine at a lower potential of 160 mV. The selective determination of dopamine in the presence of 100 times higher concentration of ascorbic acid was achieved by differential pulse voltammetry. The modified electrode offered a simple, selective and sensitive determination of low levels of dopamine. Also the oxidation over potential was reduced to an extent of 360 mV comparing with the bare graphite electrode. The proposed sensor has the advantage of easy fabrication, low cost, good sensitivity, reproducibility and stability.


2016 ◽  
Vol 8 (38) ◽  
pp. 6974-6981 ◽  
Author(s):  
Kathiresan Vijayaraj ◽  
Suck Won Hong ◽  
Sung-Ho Jin ◽  
Seung-Cheol Chang ◽  
Deog-Su Park

A disposable glucose biosensor has been fabricated on the surface of a cost-effective pencil graphite electrode (PGE) by an electrochemical method, using glucose oxidase (GOx) and reduced graphene oxide (rGO).


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