  Bolometric detectors are excellent devices for the investigation of
neutrinoless double-beta decay (0$\nu\beta\beta$). The observation of such
decay would demonstrate the violation of lepton number, and at the same time it
would necessarily imply that neutrinos have a Majorana character. The
sensitivity of cryogenic detectors based on TeO$_2$ is strongly limited by the
alpha background in the region of interest for the 0$\nu\beta\beta$ of
$^{130}$Te. It has been demonstrated that particle discrimination in TeO$_2$
bolometers is possible measuring the Cherenkov light produced by particle
interactions. However an event-by-event discrimination with NTD-based light
detectors has to be demonstrated. We will discuss the performance of a
highly-sensitive light detector exploiting the Neganov-Luke effect for signal
amplification. The detector, being operated with NTD-thermistor and coupled to
a 750 g TeO$_2$ crystal, shows the ability for an event-by-event identification
of electron/gamma and alpha particles. The extremely low detector baseline
noise, RMS 19 eV, demonstrates the possibility to enhance the sensitivity of
TeO$_2$-based 0$\nu\beta\beta$ experiment to an unprecedented level.
