An electrochemical sensor based on L-cysteine SAM imprinted by L-serine has been developed for the detection of L-serine. The sensor shows some entantioselectivity toward L-serine and a stable response establishes within 5 min. The peak current intensity of potassium ferricyanide quantified by differential pulse voltammetry (DPV) decreased linearly with increasing L-serine concentration from 10 to 100 μM with a gradient of 20.91 nA μM−1. The detection limit was 4.32 μM. The coefficient of enantiometric selectivity of the molecularly imprinted SAM was about 3.0. Compounds with similar structure as serine caused much less response.