1) They're usually too big (~30 nm) and thus may not be able to fit in very small morphological regions such as the synaptic cleft, which are usually about 20 nm wide.
Three problems with quantum dots for in vivo…
1) They're usually too big (~30 nm) and thus may not be able to fit in very small morphological regions such as the synaptic cleft, which are usually about 20 nm wide.