Screening of anomalies in a double-stranded DNA via global electrical measurements

We conduct two-terminal charge transport calculations to detect biological defects in three types of DNA sequences: periodic, quasi-periodic and random. By employing a tight-binding method coupled with Green’s function technique and Landauer-Büttiker formalism we identified signatures of base-pair mismatches in their transport properties. Our results show distinct evidence of base-pair mismatches in transmission coefficients and characteristic I–V responses, even in the presence of environmental effects. We demonstrate that by studying global charge transport properties, one can differentiate a defective DNA sequence from a pure one, even in a sample with a low (1%) contamination level. Additionally, careful examination can reveal the relative position of a base-pair mismatch in a DNA sequence. While our study focused on DNA, this method can also be applied to other biomolecules such as RNA and proteins to screen defective sites therein. This observation could lead to a new screening technique that can be applied before whole genome sequencing, saving time and resources.