We have the following suggestions for you:

Casa 400
Eerste Ringdijkstraat 4
1097 BC Amsterdam
Close to Amstel Station, 10 minutes bus ride to Science Park

IBIS Amsterdam Centre
Stationsplein 49,
1012 AB Amsterdam
Near Amsterdam Centraal Station with a direct train to the Science Park

Amsterdam Tropen Hotel
Linnaeusstraat 2C,
1092 CK Amsterdam
Close to Station Muiderpoort, direct train to Science Park

Any hotel in the Amsterdam Central Station area, from there you can take the direct train to Science Park.

The hotels can be booked through