We present cross-talk calculations for a subdiffraction nanophotonic waveguide that consists of a colloidal quantum dot (QD) array $10\mathrm{nm}$ in diameter and compare the results with conventional continuous dielectric waveguides, assuming the same $10\mathrm{nm}$ size as well as a $200\mathrm{nm}$ cutoff diameter for guided mode. We find that the QD cascade has much lower cross talk than $10\mathrm{nm}$ dielectric waveguides at an identical separation $>30\mathrm{nm}$ . Moreover, results for $200\mathrm{nm}$ dielectric waveguides at a $280\mathrm{nm}$ gap are comparable with those of QD structures spaced $110\mathrm{nm}$ apart. Hence the proposed QD device is potentially superior to conventional waveguides in achieving lower cross talk in the subdiffraction regime and provides a new route to achieving high-density photonic integrated circuits.