High throughput sensing of multiple amino acids with differential pulse voltammetry measurement

The content of amino acids in human body is closely related to human health and plays an important role in physiological regulation and medical function. In order to recognize a variety of amino acids, an electrochemical sensor array based on poly(3,4-ethylenedioxythiophene) (PEDOT) electrode was established by using two kinds of electropolymerizers, i.e., citrate and the mixture of citrate and potassium nitrate as sensing elements. Different electropolymerizers lead result in different amount of negative charge on PEDOT electrode, which leads to different adsorption capacity for positive charge amino acids and different repulsion capacity for negative charge amino acids, bringing about obvious changes in differential pulse voltammetry (DPV) current. The five amino acids were accurately identified by linear discriminant analysis (LDA), and the electrochemical sensor array was successfully applied in the differential detection of amino acids in milk.