A novel glucose ENFET based on the special reactivity of MnO2 nanoparticles.
Generally a glucose-sensitive enzyme field-effect transistor (ENFET) is based on local pH change in biomembranes resulted from the formation of gluconic acid. Here we proposed a glucose ENFET based on a new principle. The glucose ENFET was fabricated by coimmobilizing glucose oxidase (GOD) and MnO(2) nanoparticles on the gate of an ion-sensitive field-effect transistor (ISFET). The proposed glucose biosensor shows a significant local pH increase in the sensitive membrane with the increase of glucose concentration. The driving force of the pH change in our sensor is essentially different from all the other glucose ENFETs, including those prepared by bulk MnO(2). The special reaction ability of MnO(2) nanoparticles with hydrogen peroxide might be the main cause of the pH change. In addition, the influence of buffer concentration, pH and ionic strength on the glucose ENFET is investigated in detail. It is found that the ionic strength has little effect on the performance of the ENFET. Under optimal conditions, the proposed ENFET exhibits a linear response with glucose in the range of 0.025-1.90 mM, an extended dynamic upper limit of 3.5 mM glucose, and considerable good reproducibility and stability.
Luo
Xi-Liang
XL
Department of Chemistry, The State Key Laboratory of Coordination Chemistry, Institute of Analytical Science, Nanjing University, Nanjing 210093, PR China.
Xu
Jing-Juan
JJ
Zhao
Wei
W
Chen
Hong-Yuan
HY
D015374:Biosensing Techniques; D005947:Glucose / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D017895:Manganese Compounds; D036103:Nanotechnology; D010087:Oxides; D013053:Spectrophotometry; D013997:Time Factors; D014325:Tromethamine
D017895:Manganese Compounds; D010087:Oxides; D014325:Tromethamine; D005947:Glucose; C016552:manganese dioxide