Solution-gated transistor based on electrochemically reduced graphene oxide channel

Nitrite is one of the most commonly measured indicators in environmental monitoring due to its detrimental effects on environmental safety and human health. It is vital to develop simple and sensitive nitrite detection strategy. In this study, the solution-gated transistor sensor based on electrochemically reduced graphene oxide (ERGO) as the channel of the device was designed and fabricated to realize the sensitive detection of nitrite, in which Au nanoparticles/reduced graphene oxide (AuNPs/RGO) nanocomposites were functionalized the gate electrode for non-enzymatic electrocatalytic oxidation of the nitrite. The sensing principle of the electrochemically reduced graphene transistor (ERGT) is attributed to the change of the effective gate voltage caused by the electrooxidation of nitrite at the gate, thereby regulating the channel current. Due to the high electrical conductivity of ERGO and the superior electrocatalytic property of AuNPs/RGO nanocomposites, the as-prepared transistor sensor showed superior sensing performance toward nitrite detection, including low-detection limit (1 nM), ultra-wide detection range (1 nM-15 mM), good anti-interference ability and long-term stability (86.1% current response retention after 15 days). Nitrite in natural lake water has been accurately detected by our device to prove its practicability, suggesting that the ERGT sensor can be served as a new platform to realize the highly sensitive nitrite detection in environmental and food safety monitoring. [GRAPHICS] .