  Cyanides, ranging from three carbon atoms to PAHs, and alkenyl compounds are
abundant in the interstellar medium (ISM). Aminoacrylonitrile
(3-Amino-2-propenenitrile, H$_{2}$N-CH=CH-CN), an alkenyl cyanide, thus
represents a promising candidate for new interstellar detection. A
comprehensive spectroscopic laboratory investigation of aminoacrylonitrile in
its rotational ground vibrational state has been herein performed. The
measurements carried out up to the THz regime made it possible to generate a
precise set of reliable rest frequencies for its search in space up to
sub-millimetre wavelengths. The $Z$-aminoacrylonitrile ($Z$-apn) isomer
spectrum has been recorded employing a source-modulated sub-millimetre
spectrometer, from 80 GHz to 1 THz. A combination of Doppler and sub-Doppler
measurement regimes allowed to record 600 new lines. The collected data have
enabled the characterisation of a set of spectroscopic parameters up to decic
centrifugal distortion constants. The catalogue generated from the improved
spectral data has been used for the search of $Z$-apn in the spectral survey of
the G+0.693-0.027 molecular cloud located in the central molecular zone, in the
proximity of the Galactic centre.
