Selective and sensitive electrochemical sensing of gastrodin based on nickel foam modified with reduced graphene oxide/silver nanoparticles complex-encapsulated molecularly imprinted polymers

In this work, a facile one-step electrochemical coreduction method was developed to synthesize reduced graphene oxide (rGO) and silver nanoparticles (AgNPs) onto the surface of nickel foam (NF). Using graphene oxide and Ag(NH3)(2)OH as precursors, rGO and AgNPs were co-deposited on NF surface. The rGO-AgNPs modified NF was covered with molecularly imprinted polymers (MIPs) through in-situ electro-polymerization of pyrrole in the presence of gastrodin (GAS). After the elution of templated GAS molecules, poly(pyrrole)-based MIPs were covered on the surface of rGO-AgNPs modified NF to form MIPs/rGO-AgNPs/NF system. The system as a novel working electrode exhibited sensitive and selective electrochemical signal responses towards GAS. Under optimal conditions, MIPs/ rGO-AgNPs/NF had a nearly linear relationship between the oxidation current peak intensities and GAS concentration in the range of 0.01-1 mu M (R-2= 0.9919), with a low limit of detection of 1 nM. MIPs/rGO-AgNPs/NF was used as a novel MIPs electrochemical GAS sensor that showed an excellent capability of GAS detection, over potential interferents. In human serum samples, the detection of GAS based on this sensor had high detection stability and recovery. Experimental results demonstrated a high feasibility of MIPs/rGO-AgNPs/NF for GAS detection in real samples.