Amperometric immunosensor for the determination of α-1-fetoprotein based on multiwalled carbon nanotube-silver nanoparticle composite.
A new amperometric immunosensor for the determination of α-1-fetoprotein (AFP) has been constructed. First, a multiwalled carbon nanotube-silver (MWNT-Ag) composite was modified on the surface of a glassy carbon electrode. Then, chitosan-MnO(2) (CS-MnO(2)) with excellent film forming ability was dipped onto the MWNT-Ag-modified electrode. Subsequently, gold nanoparticles were electrodeposited on the electrode to immobilize anti-AFP. The assembly processes were characterized with cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. MWNT-Ag composite was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-vis spectroscopy. The system was optimized to realize a reliable determination of AFP in the range of 0.25-250 ng/ml with a detection limit of 0.08 ng/ml (S/N=3). The proposed immunosensor showed a rapid and highly sensitive amperometric response to AFP with acceptable stability and reproducibility.
Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, 400715 Chongqing, China.
Xin
X
Che
Ruo
R
Yuan
Yaqin
Y
Chai
Jingjing
J
Li
Zhongju
Z
Song
Jinfen
J
Wang
D000818:Animals; D000906:Antibodies / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D017097:Electric Impedance; D004566:Electrodes; D053768:Metal Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D000509:alpha-Fetoproteins / Q000032:analysis* / Q000737:chemistry
D000906:Antibodies; D037742:Nanotubes, Carbon; D000509:alpha-Fetoproteins; D012834:Silver