US EPA

7468243 

Journal Article 

A screen-printed electrode modified with tungsten disulfide nanosheets for nanomolar detection of the arsenic drug roxarsone 

Govindasamy, M; Wang, SF; Jothiramalingam, R; Noora Ibrahim, S; Al-Lohedan, HA 

2019 

1 

Microchimica Acta
ISSN: 0026-3672
EISSN: 1436-5073 

186 

7 

420 

English 

31187268 

10.1007/s00604-019-3535-1 

WOS:000471343700009 

A sensitive electrochemical (voltammetric; DPV) sensor has been developed for the determination of coccidiostat drug (roxarsone) based on the use of an SPCE (screen-printed carbon electrode) modified with tungsten disulfide nanosheets (WS2 NSs). The electrochemical detection of roxarsone on the WS2-modified SPCE was examined by electrochemical strategies. XPS, XRD, Raman, SEM, TEM, EDS and EIS were used to characterize the nanosheets. The effects of scan rate, pH values (phosphate buffer) and buffer concentration were optimized. A selective roxarsone sensor was developed that works best at -0.64 V (vs. Ag/AgCl) and performs much better than the bare SPCE. Features include (a) a wider linear range (0.05 to 490 μM), (b) a nanomolar detection limit (0.03 μM) and (c) high sensitivity (29 μA·μM-1·cm-2). The modified SPCEs have been successfully applied to the determination of roxarsone in spiked meat samples where they gave high accuracy and good recoveries. Graphical abstract Synthesis of WS2 nanosheets and electrochemical detection of roxarsone.