As complementary metal-oxide-semiconductor (CMOS) process technologies scale below the sub 50-nm feature sizes, the conventional top-down approaches need to be modified to cope with the increased process variations, interconnect processing difficulties, and other newly aggravated physical effects. These techniques result in increased cost of production and longer time to market. In contrast, “bottoms-up” techniques are potentially less expensive, with feature sizes comparable to molecular dimensions. DNA, for example, is an attractive candidate to realize molecular nanodevices because of its intrinsic functionalities like self-assembly, molecular recognition and replication. This review article discusses important patents and approaches that describe the design and realization of DNA based nanoelectronics using bottoms-up techniques. First, we discuss briefly about the building blocks of molecular electronics. Next, we will report on approaches for the fabrication of DNA-templated nanowires. Finally, we will discuss the inventions related to the fabrication of DNA and carbon nanotube (CNT) based transistors.