▎ 摘　　要

A cost-effective screen printed electrode modified with graphene oxide nanoribbon (GONR) is developed for the determination of folic acid (FA). GONR is prepared from multi-walled carbon nanotubes (MWCNTs) and our studies revealing that the electrocatalytic ability of MWCNTs is greatly improved in GONR. The GONR is successfully characterized by SEM, EDX and impedance analysis. Next, GONR was deposited on the pretreated screen printed carbon electrode (SPCE) and the resulting GONR/SPCE was used to study the electrocatalysis of FA. The fabricated modified electrode has excellent electrocatalytic ability to detect FA. The effect of scan rate and pH towards electrocatalysis of FA is studied in detailed. The electrode detects FA in wide linear range of 0.1-1600 mu M and achieves low detection limit of 20 nM. The sensor performance of the GONR/SPCE is either superior or comparable to the previously published FA sensors. Moreover, the electrode has good repeatability, reproducibility, stability and practicality.