Carbonized silk fabric-based flexible organic electrochemical transistors for highly sensitive and selective dopamine detection

In this work, Nafion and reduced graphene oxide-wrapped carbonized silk fabric (Nafion/rGO/CSF) were fabricated into a precious metal-free gate electrode for organic electrochemical transistor (OECT) sensors. The hierarchical structure of CSF can effectively increase the conductivity of the electrode and avoid the aggregation of rGO and Nafion, giving the Nafion/rGO/CSF-based OECT sensors excellent detection capability towards dopamine (DA) with an ultralow detection limit of 1 nM, a broad detection range from 1 nM - 30 mu M and a high selectivity. Moreover, the outstanding electrochemical sensing behaviors of the Nafion/rGO/CSF-based OECT sensor are retainable under bent states and in artificial urine, which will greatly facilitate its application in flexible electronics. The abovemenitoned results indicate that OECT sensors with carbon-based gate electrodes can also obtain high sensitivity comparable to that of precious metal gate electrodes, which, therefore, provides an unprecedented strategy for manufacturing flexible OECT sensors with high performance and low cost.