Detection of biomarkers with carbon nanotube-based immunosensors.
A facile and capable method of preparation of sensitive carbon nanotube (CNT)/polysulfone/RIgG immunosensor is discussed in this chapter. The immunosensor is based on the modification of disposable screen-printed electrodes by phase inversion method. CNT/polysulfone membrane acts as the reservoir of immunomolecules as well as a transducer. This configuration offers large surface area, elevated porosity, and mechanical flexibility. The comparison with graphite/polysulfone/RIgG immunosensors shows a significantly improved sensitivity for those prepared with CNTs coupled with polysulfone (PSf). The immunosensing scheme is based on the competitive assay between free and labeled anti-RIgG for the available binding sites of immobilized rabbit IgG (RIgG). The RIgG is incorporated into the PSf immunosensor using a phase inversion method. Horseradish peroxidase enzyme is used as label and hydroquinone as electrochemical mediator. The limit of detection for competitive assay is 1.66 microg/mL. The sensitivity is six times higher for MWCNT-based than for graphite-based electrodes.
Sánchez
Samuel
S
Sensors and Biosensors Group, Analytical Chemistry Department, UAB. Edifici Cn, Bellaterra, Spain.
Fàbregas
Esteve
E
Pumera
Martin
M
D000327:Adsorption; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D015374:Biosensing Techniques; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism; D007074:Immunoglobulin G / Q000032:analysis*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D016062:Porosity; D011817:Rabbits; D012680:Sensitivity and Specificity; D013499:Surface Properties
D015415:Biomarkers; D020099:Coated Materials, Biocompatible; D007074:Immunoglobulin G; D037742:Nanotubes, Carbon; D006735:Horseradish Peroxidase