Fast and sensitive detection of Pb2+ in foods using disposable screen-printed electrode modified by reduced graphene oxide.
In this study, reduced graphene oxide (rGO) was electrochemically deposited on the surface of screen-printed carbon electrodes (SPCE) to prepare a disposable sensor for fast detection of Pb2+ in foods. The SEM images showed that the rGO was homogeneously deposited onto the electrode surface with a wrinkled nanostructure, which provided 2D bridges for electron transport and a larger active area for Pb2+ adsorption. Results showed that rGO modification enhanced the activity of the electrode surface, and significantly improved the electrochemical properties of SPCE. The rGO modified SPCE (rGO-SPCE) was applied to detect Pb2+ in standard aqueous solution, showing a sharp stripping peak and a relatively constant peak potential in square wave anodic stripping voltammetry (SWASV). The linear range for Pb2+ detection was 5~200 ppb (R2 = 0.9923) with a low detection limit of 1 ppb (S/N = 3). The interference of Cd2+ and Cu2+ at low concentrations was effectively avoided. Finally, the rGO-SPCE was used for determination of lead in real tap water, juice, preserved eggs and tea samples. Compared with results from graphite furnace atomic absorption spectroscopy (GFAAS), the results based on rGO-SPCE were both accurate and reliable, suggesting that the disposable sensor has great potential in application for fast, sensitive and low-cost detection of Pb2+ in foods.
College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China. guoxs@zju.edu.cn.
Jin-Ming
JM
Jian
Yan-Yan
YY
Liu
Ye-Lei
YL
Zhang
Xi-Shan
XS
Guo
Qiang
Q
Cai
D003217:Conductometry / Q000295:instrumentation*; D004209:Disposable Equipment; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation*; D005506:Food Contamination / Q000032:analysis*; D006108:Graphite / Q000737:chemistry*; D007854:Lead / Q000032:analysis*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D010087:Oxides; D007854:Lead; D006108:Graphite