Either it's a very modern piece, or it's a romantic piece..
If it's a modern piece, you should probably do an actual pizzicato, on the string...
Though, somehow I doubt it's a modern piece. If it's romantic, I wouldn't take it too literally. A very big part of the romantic music was to imagine something that was impossible to do.
Schumann wrote accents on a sustained note, which is impossible to do.. you know, since it's sustained note. He also wrote a singing line as a middle staff, in his Arabesque, with the text "Don't sing it out loud, but in your head"-sort of... Aaaand he wrote (with italian words): "As fast as you" can on one bar, and "Even faster" some bars later.
Chopin (and many many more) wrote crescendo on a single tone.
Liszt wrote, in his sonetto del petrarca no 104, "vibrato".
Pizzicato would not be very strange to notate. It's more as if you would hear it as a pizzicato than just a staccato. It's different!