Highly sensitive glucose biosensor based on Au-Ni coaxial nanorod array having high aspect ratio.
An effective glucose biosensor requires a sufficient amount of GOx immobilizing on the electrode surface. An electrode of a 3D nanorod array, having a larger surface-to-volume ratio than a 2D nanostructure, can accommodate more GOx molecules to immobilize onto the surface of the nanorods. In this study, a highly sensitive Au-Ni coaxial nanorod array electrode fabricated through the integration of nano electroforming and immersion gold (IG) method for glucose detection was developed. The average diameter of the as-synthesized Ni nanorods and that of the Au-Ni nanorods were estimated to be 150 and 250 nm, respectively; both had a height of 30 μm. The aspect ratio was 120. Compared to that of a flat Au electrode, the effective sensing area was enhanced by 79.8 folds. Actual glucose detections demonstrated that the proposed Au-Ni coaxial nanorod array electrode could operate in a linear range of 27.5 μM-27.5mM with a detection limit of 5.5μM and a very high sensitivity of 769.6 μA mM(-1)cm(-2). Good selectivity of the proposed sensing device was verified by sequential injections of uric acid (UA) and ascorbic acid (AA). Long-term stability was examined through successive detections over a period of 30 days.
Department of Mechanical Engineering, National Chung-Hsing University, Taichung 40227, Taiwan.
Che-Wei
CW
Hsu
Department of Mechanical Engineering, National Chung-Hsing University, Taichung 40227, Taiwan; Graduate Institute of Biomedical Engineering, National Chung-Hsing University, Taichung 40227, Taiwan. Electronic address: gjwang@dragon.nchu.edu.tw.
Gou-Jen
GJ
Wang
D015374:Biosensing Techniques / Q000379:methods*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000737:chemistry / Q000378:metabolism; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D008958:Models, Molecular; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D009532:Nickel / Q000737:chemistry*
D004800:Enzymes, Immobilized; D006046:Gold; D009532:Nickel; D005949:Glucose Oxidase; D005947:Glucose
Glucose biosensor; High sensitivity; High-aspect-ratio Au–Ni coaxial nanorod array; Immersion gold