Electrode surface rebuilding for electrochemical assembling of conductive PEDOT:PSS hydrogel towards biosensing

Conductive hydrogels have shown promise in a wide range of electrochemical sensing applications. Decorating conductive hydrogel on the electrode surface is a key technical challenge. Herein, we have constructed a method to achieve better and stable attachment between conductive hydrogel and electrode by surface rebuilding technique. Electrochemical gelation of poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT:PSS) hydrogels on gold electrodes that have undergone surface rebuilding method were then made into several biosensors for electrochemical sensing of H2O2, glucose, dopamine (DA) and levodopa (L-Dopa) respectively. The H2O2 sensor shown a linear range from 0 to 1 mM with ultrahigh sensitivity of 1988.66 μA⋅cm−2⋅mM−1. The sensor responded to glucose ranging from 0 to 14 mM with high sensitivity of 198.047 μA⋅cm−2⋅mM−1. The sensor responded to DA ranging from 0 to 1 mM with high sensitivity of 145.047 μA⋅cm−2⋅mM−1, and to L-Dopa ranging from 0 to 0.5 mM with high sensitivity of 982.21 μA⋅cm−2⋅mM−1. We initially verify the gold surface rebuilding method in solving the problem of difficult combination of electrochemical mediated hydrogel and electrode, the method could be explored further for various promising applications in hydrogel electronics in the future.