Construction and Application of Flow Enzymatic Biosensor Based of Silver Solid Amalgam Electrode for Determination of Sarcosine

In this paper, the flow amperometric enzymatic biosensor based on polished silver solid amalgam electrode for determination of sarcosine in model sample under flow injection analysis conditions is presented. The biosensor works on principle of electrochemical detection of oxygen decrease during enzymatic reaction which is directly proportional to the concentration of sarcosine in sample. The whole preparation process takes about 3 h. The RSD of repeatability of 10 consecutive measurements is 1.6 % (csarcosine=1.0×10−4 mol dm−3). Under optimal conditions the calibration dependence was linear in the range 7.5×10−6–5.0×10−4 mol dm−3 and limit of detection was 2.0×10−6 mol dm−3.