Direct electrochemistry of hemoglobin immobilized on the water-soluble phosphonate functionalized multi-walled carbon nanotubes and its application to nitric oxide biosensing.
The direct electron transfer and electrocatalysis of hemoglobin (Hb) immobilized on the phosphonate functionalized multi-walled carbon nanotubes (MWCNTs) are investigated. Fourier transform infrared (FT-IR) spectra, UV-vis spectra and cyclic voltammetry (CV) analyses reveal that the phosphonate functionalized MWCNTs have good biocompatibility for Hb immobilization, and promote the electron communication between Hb and electrode. The immobilized Hb shows a pair of redox peak with a formal potential of -406 ± 10 mV (vs. SCE) and the electrochemical behavior of Hb was a surface-controlled process in a pH 7.0 phosphate buffer solution. And the immobilized Hb can act in an electrocatalytic manner in the electrochemical reduction of nitric oxide (NO). Accordingly, an unmediated NO electrochemical biosensor is constructed. Under optimized experimental conditions, the NO electrochemical biosensor shows the fast response (less than 3s), the wide linear range (1.5 × 10(-7) to 2.7 × 10(-4)M) and the low detection limit (1.5 × 10(-8)M), which is attributed to the good mass transport, the large Hb loading per unit area and the fast electron transfer rate of Hb.
Jiangsu Key Laboratory of New Power Batteries, Center for Analysis and Testing, Laboratory of Electrochemistry, College of Chemistry and Materials Science, Nanjing Normal University, 1♯ Wenyuan Road, Nanjing 210023, PR China.
Pan
P
Li
Yu
Y
Ding
Zhaoyang
Z
Lu
Ying
Y
Li
Xiaoshu
X
Zhu
Yiming
Y
Zhou
Yawen
Y
Tang
Yu
Y
Chen
Chenxin
C
Cai
Tianhong
T
Lu
D000818:Animals; D055162:Biocatalysis; D015374:Biosensing Techniques; D002417:Cattle; D055664:Electrochemical Techniques; D004579:Electron Transport; D006454:Hemoglobins / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D055767:Immobilized Proteins / Q000737:chemistry*; D057230:Limit of Detection; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009569:Nitric Oxide / Q000032:analysis*; D010757:Phosphorous Acids / Q000737:chemistry*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared
D006454:Hemoglobins; D055767:Immobilized Proteins; D037742:Nanotubes, Carbon; D010757:Phosphorous Acids; D012996:Solutions; C570063:phosphonic acid; D009569:Nitric Oxide; D006861:Hydrogen Peroxide
Carbon nanotubes; Direct electrochemistry; Electrocatalysis; Hemoglobin; Phosphonic acid groups