COMPARATIVE VOLTAMMETRIC STUDIES OF IMMUNOGLOBULINS AND DNP-LABELED IMMUNOGLOBULINS

A comparative electrochemical study of human immunoglobulins IgG(1) an d IgG(3) carried out at a hanging mercury drop electrode shows that me chanisms other than the reduction of interchain disulphide linkages ar e responsible for the cathodic peaks observed for such proteins. Consi dering that the nature of the electrochemical process observed for imm unoglobulins are poorly defined and not fully understood, a new approa ch to the electrochemical determination of such proteins, involving th e use of 2,4-dinitrophenol (DNP) as a label, has been developed. Dynam ic linear ranges of nearly two magnitudes and detection limits below 1 0(-10) M were achieved. (C) 1997 Elsevier Science B.V.