Additional file 1: Fig. S1. Typical photographs of TMB–H2O2 solution (left) TMB–H2O2-Au NRs (middle) and TMB–H2O2-Au@Pt NRs (right). Reaction conditions: 0.5 mM TMB, 20 mM H2O2 and 0.125 nM Au NRs/Au@Pt NRs. Fig. S2. Effects of substrates concentration (TMB), substrates concentration (H2O2), conjugate concentration (Au@Pt NR-antigen conjugates), temperature, reaction time and pH on catalytic activity of the Au@Pt NR-antigen conjugates. Reaction conditions: (A) 0.125 nM Au@Pt NRs, 20 mM H2O2, (B) 0.125 nM Au@Pt NRs and 0.5 mM TMB, (C) 0.5 mM TMB and 20 mM H2O2, (D-F) 0.125 nM Au@Pt NRs, 0.5 mM TMB and 20 mM H2O2