Most synth pedals will get close to that. The main thing is to have a no attack time and a short decay time.
Synth pedals start with the Boss SYB-5, going up through the MarkBass Super Synth and on to the Akai Deep Impact (discontinued and expensive second-hand).
Search for 'synth' on this Effects forum and you'll find tons of threads about synth pedals.
Or you could just try an envelope filter. Set the decay time of the filter to be short, and the frequency low, so that the note almost disappears after the decay. Then set the sensitivity so you get enough 'bow' sound when the filter opens.
Add an octave pedal or fuzz before the envelope filter for a bigger synthier sound, or setup a similar patch in a multi-effect processor like the Zoom B3. The B3 also has synth effects in it that would nail this sound.