Novel renewable immunosensors based on temperature-sensitive PNIPAAm bioconjugates.
A novel renewable immunosensor was created comprising a temperature-controlled surface composed of poly(n-isopropylacrylamide) (PNIPAAm)-antibody conjugates that could reversibly bind the antigen. Bovine serum albumin (BSA) and the corresponding antibody (anti-BSA) were chosen as a model antibody-antigen system to demonstrate the concept. The thermally responsive PNIPAAm conjugated to anti-BSA displayed a controllable conformation change between an expanded and a collapsed form, below and above its characteristic phase transition temperature, i.e. low critical solution temperature (LCST). This showed a remarkable change in the bioaffinity of the conjugate for BSA. Thus, a renewable anti-BSA surface was generated for re-binding of the target antigen at the thermally controllable PNIPAAm-anti-BSA conjugated surface. The temperature-controlling strategy resulted in the regeneration of immunosensors on which immobilized anti-BSA antibodies retained their activity and specificity for more than 30 reproducible assays. The level of dissociation reached 89%, which is comparable with established recovery methods, while offering easer handing. The controlled binding and dissociation were monitored by quartz crystal microbalance (QCM), confocal fluorescence, native electrophoresis, laser-induced fluorescence, and electrochemical impedance methods.
Liu
Ying
Y
Department of Chemistry & Institutes of Biomedical Sciences, Fudan University, China.
Meng
Sheng
S
Mu
Li
L
Jin
Guiying
G
Zhong
Wei
W
Kong
Jilie
J
D000178:Acrylamides / Q000737:chemistry*; D000180:Acrylic Resins; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017743:Equipment Reuse; D007118:Immunoassay / Q000295:instrumentation*; D011108:Polymers / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012710:Serum Albumin, Bovine / Q000032:analysis*; D013696:Temperature
D000178:Acrylamides; D000180:Acrylic Resins; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D012710:Serum Albumin, Bovine