A highly sensitive method for detecting oligonucleotide targets has been developed using quantum dot (QD) functionalized nanotubes (NTs) that contain a cascade energy band-gap architecture. Their assembly with different types of QDs by the layer-by-layer (LBL) allowed for the formation of fluorescence resonance energy transfer (FRET) structures in the NTs resulting in an enhanced fluorescence emission from dye labeled oligonucleotide targets captured by probe DNA through hybridization. This approach results in a significant enhancement of detection of dye labeled oligonucleotide targets. The promising increase in detection sensitivity allows for low detection limits by tuning the QD emission, adding other types of QDs, or adjusting the distance between all photoactive compounds in the NTs. Hence, the strategy used here to produce new hybrid materials may pave a way for broadening application of NTs in the field of biochemical materials, e.g. sensitive biosensors.