Electrochemical sensor using carbon nanotube composites for chronicdegenerative diseases diagnosis

Sensitive and selective detection for cancer biomarkers is critical in cancer clinical diagnostics. In this work, we report an electrochemical detection platform for the carbohydrate antigen tumor marker 15-3 (CA15-3). It is based on a composite material of poly [2-methoxy-5- (2-ethylhexyloxy) -1, 4-phenylenevinylene] (MEH-PPV) and multiwalled carbon nanotubes (MWCNT), which deposited as active layer of an organic thinfilm transistor. This layer was surface functionalized with the Anti-CA15-3 monoclonal antibody. The devices have a favorable electrical output response for VSD source-drain potentials between 0 to 5 volts, and VG as 8 volts. Once the antigen (CA15-3) is recognized by the antibody, the electrical response is diminished. The test has a linear response in the concentration range of 0-30 U mL - 1 of CA 15-3, with a lower detection limit of ~1 U mL - 1 and a stability of 90% with respect to the initial values after storing the device for two weeks. The method was successfully applied to the determination of CA15-3 in serum samples. Possibly, this used composite material has a greater scope and can be applied to another type of detection scheme.