Impedance-based DNA switches for solving the Boolean logic circuit†

Abstract

DNA has been extensively used for molecular computing because of its highly precise Watson–Crick base pairing. In this study, we have exploited epigenetic variations in DNA to construct simple Boolean logic circuit gates that can give AND, OR, NOT, NAND, and NOR outputs in under five minutes. Results are demonstrated using 77-mer long oligonucleotides that have varied degrees of methylation. This differential methylation leads to aggregation-induced structural changes in the oligomers that in turn impact their electro-physiochemical properties and impedance signal. Using these characteristics, complex DNA-based methyl-logic gates were solved for four input conditions [(0, 0), (0, 1), (1, 0), (1, 1)]. The performance analysis gave a sensitivity of 96.8% and a specificity of 98.75%. This impedance-based technique for solving Boolean circuits offered faster processing speed, robust outputs, fewer complex steps or kinetic reaction cascades, and being label-free. This research opens possibilities of conducting massive size computations and solving biological circuits using DNA.