Label-free detection of antibody-antigen interactions on (R)-lipo-diaza-18-crown-6 self-assembled monolayer modified gold electrodes.
Novel (R)-diaza-18-crown-6 has been prepared by a simple two-step synthetic method and characterized for its ability to form a uniform self-assembled monolayer (SAM) on gold as well as to immobilize proteins using atomic force microscopy, quartz crystal microbalance, and electrochemical impedance spectroscopy (EIS) experiments. The (R)-lipo-diaza-18-crown-6 was shown to form a well-defined SAM on gold, which subsequently captures the antibody (Ab) molecules that in turn capture the antigen (Ag) molecules. The Ab molecules studied include antibody C-reactive protein (Ab-CRP) and antibody ferritin (Ab-ferritin) along with their Ag's, i.e., CRP and ferritin. Quantitative detection of the Ab-Ag interactions was accomplished by EIS experiments with a Fe(CN)6(3-/4-) redox probe present. The ratios of the charge-transfer resistances for the redox probe on the SAM-antibody-covered electrode to those with the antigen molecules attached show an excellent linearity for log[Ag] with lower detection limits than those of other SAMs for the electrochemical sensing of proteins.
Park
Jin-Young
JY
Department of Chemistry, Pohang University of Science and Technology, Pohang, Gyeongbuk 790-784, Korea.
Lee
Yoon-Suk
YS
Kim
Byeang Hyean
BH
Park
Su-Moon
SM
D000906:Antibodies / Q000032:analysis* / Q000276:immunology; D000937:Antigen-Antibody Reactions; D000941:Antigens / Q000032:analysis* / Q000276:immunology; D002097:C-Reactive Protein / Q000032:analysis / Q000276:immunology; D003198:Computer Simulation; D047248:Crown Compounds / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D005293:Ferritins / Q000032:analysis / Q000276:immunology; D006046:Gold / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D013057:Spectrum Analysis; D008063:Thioctic Acid / Q000031:analogs & derivatives*
D000906:Antibodies; D000941:Antigens; D047248:Crown Compounds; D008063:Thioctic Acid; D006046:Gold; D002097:C-Reactive Protein; D005293:Ferritins