Embedded WS2 microballs and circular nanodisks are efficiently synthesized using sodium dodecyl sulfate (SDS) and cysteine by a controlled and low cost hydrothermal method. The addition of SDS provoked symmetry in the circular architectures of WS2 nanostructures. The as-prepared WS2 embedded nano/microstructures exhibited good optical UV absorption spectra in the visible region. In addition, embedded WS2 circular nanodisks are exposed to ethanol gas and exhibited high gas–sensing responses for different concentrations of gas. The trends in structure designing of dichalcogenide may turn a new insight for gas-sensing areas.