title: An improved ELISA with linear sweep voltammetry detection.
abstract: An improved ELISA combined with linear sweep voltammetry detection of p-nitrophenol generated by an enzyme has been investigated in this study. p-nitrophenol, produced from alkaline phosphatase catalysing p-nitrophenyl phosphate, yielded an oxidative peak at 1.06 V (vs. Ag/AgCl) with a wax-impregnated tubular graphite anode. Without separation, the small three-electrode system was directly inserted in the well of an ELISA plate for detection. The detection limit for p-nitrophenol was 1 x 10(-6) M, lower than that obtained by measuring the absorbance of p-nitrophenol. The feasibility of utilizing linear sweep voltammetry as a detection scheme was demonstrated by determining metallothionein, granulocyte-colony stimulating factor and Xenopus laevis keratin using the above new system. The method was simple, reproducible and much more sensitive than traditional spectrophotometry.
authors.affiliation: Department of Technical Physics, Peking University, Beijing, People's Republic of China.
authors.forename: F
authors.initials: F
authors.lastname: Tie
authors.forename: A
authors.initials: A
authors.lastname: Pan
authors.forename: B
authors.initials: B
authors.lastname: Ru
authors.forename: W
authors.initials: W
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Hu
mesh_terms: D000818:Animals; D004563:Electrochemistry; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000032:analysis; D007633:Keratins / Q000032:analysis; D008099:Liver / Q000378:metabolism; D008668:Metallothionein / Q000032:analysis; D051379:Mice; D009596:Nitrophenols / Q000032:analysis*; D012016:Reference Values; D012680:Sensitivity and Specificity
chemical_list: D009596:Nitrophenols; D016179:Granulocyte Colony-Stimulating Factor; D007633:Keratins; D008668:Metallothionein; C024836:4-nitrophenol