  Low barrier quasiparticle tunneling spectroscopy on
Sr$_{0.9}$La$_{0.1}$CuO$_2$ has been studied with
PtIr/Sr$_{0.9}$La$_{0.1}$CuO$_2$ point contacts at various temperatures and
magnetic fields. No zero-bias conductance peaks are observed. By fitting
tunneling conductance to Blonder-Tinkham-Klapwijk theory, the temperature
dependent s-wave superconducting gaps are obtained. The present results exclude
the possibility of d-wave symmetry for the pair gap in
Sr$_{0.9}$La$_{0.1}$CuO$_2$, and do not support the conventional phonon
mediated pairing in this system either.
