Simplify the following text for a Grade 12 native English-speaking person.
Original: In another development , the synthesis and properties of semiconductor nanocrystals was studied ; this led to a fast increasing number of metal and metal oxide nanoparticles and quantum dots .
Simplified: In another development , people studied how to make semiconductor nanocrystals . Many metal oxide nanoparticles are now used as quantum dots ( nanoparticles where the behavior of single electrons becomes important ) .