Demonstration of a new biosensing concept for immunodiagnostic applications based on change in surface conductance of antibodies after biomolecular interactions.
We report an important observation that the surface conductivity of antibody layer immobilized on polylysine-coated glass substrate decreases upon the formation of complex with their specific antigens. This change in conductivity has been observed for both monoclonal and polyclonal antibodies. The conductance of monoclonal mouse IgG immobilized on polylysine-coated glass substrate changed from 1.02x10(-8) ohm(-1) to 1.41x10(-11) ohm(-1) at 10 V when complex is formed due to the specific biomolecular interactions with rabbit anti-mouse IgG F(ab')(2). Similar behavior was observed when the same set up was tested in two clinical assays: (1) anti-Leishmania antigen polyclonal antibodies taken from Kala Azar positive patient serum interacting with Leishmania promastigote antigen, and (2) anti-p21 polyclonal antibodies interacting with p21 antigen. The proposed concept can represent a new immunodiagnostic technique and may have wide ranging applications in biosensors and nanobiotechnology too.
Vashist
Sandeep Kumar
SK
Kaur
Inderpreet
I
Bajpai
Ram Prakash
RP
Bharadwaj
Lalit Mohan
LM
Tewari
Rupinder
R
Raiteri
Roberto
R
D000818:Animals; D000936:Antigen-Antibody Complex / Q000032:analysis*; D015374:Biosensing Techniques; D004553:Electric Conductivity; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D011817:Rabbits
D000936:Antigen-Antibody Complex