The present invention describes a new glass substrate, which consisting of Na2O, Al2O3, P2O5 and SiO2, suitable for the synthesis of stable embedded gold nano- islands (GNS). In the present invention, the gold nano-islands on the surface of glass substrates are formed due to the implementation of thermal dewetting process that  include the coating of gold film followed by scheduled heat treatment. The processing parameters such as temperature and time for the formation of stabilized GNS on  the glass substrates are disclosed herein. The glass substrates with the stabilised GNS are highly suitable for the utilizations of non-linear optical saturable absorber and  also for the surface enhanced Raman spectroscopy for the detection of analytes.