Quantitative photoelectrochemical detection of biological affinity reaction: biotin-avidin interaction.
Quantitative detection of a biological affinity reaction, the biotin/avidin recognition, was achieved using our newly developed photoelectrochemical analytical system. The system is based on the operation mechanism of the well-developed dye-sensitized photoelectrochemical solar cells and comprises a ruthenium tris(2,2'-bipyridine) (Ru-bipy) derivative as the photoelectrochemical signal-generating molecule, oxalate as the sacrificial electron donor, and tin oxide nanoparticle as the semiconductor electrode material. To perform the affinity reaction, avidin was immobilized on SnO(2) electrode by passive adsorption. Biotin-linked bovine serum albumin (BSA) was labeled with an NHS-ester derivative of Ru-bipy. After binding of BSA to the surface-immobilized avidin through biotin, photoelectrochemical measurement was carried out in the presence of oxalate. Anodic photocurrent was turned on and off repeatedly by control of incidental light. The action spectrum of the photocurrent resembled the absorption spectrum of Ru-bipy, proving the photocurrent was generated from the metal complex. A linear relationship between photocurrent and BSA concentration was obtained in the range of 1-100 microg/mL. This is the first case of quantitative photoelectrochemical detection of a biological affinity interaction.
Dong
Dong
D
Zheng
Dong
D
Wang
Fu-Quan
FQ
Yang
Xi-Qiang
XQ
Wang
Na
N
Li
Yuan-Guang
YG
Guo
Liang-Hong
LH
Cheng
Jing
J
D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives / Q000737:chemistry; D001360:Avidin / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D001667:Binding, Competitive; D015374:Biosensing Techniques / Q000379:methods; D001710:Biotin / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D003102:Colloids / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D008027:Light; D010070:Oxalates / Q000737:chemistry; D010777:Photochemistry; D011485:Protein Binding; D012428:Ruthenium / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry; D017971:Tin Compounds / Q000737:chemistry
D003102:Colloids; D010070:Oxalates; D017971:Tin Compounds; D001360:Avidin; D012710:Serum Albumin, Bovine; D015082:2,2'-Dipyridyl; D001710:Biotin; D012428:Ruthenium; C045358:stannic oxide