High Sensitivity DNA-detection for Forensic Applications at Auckland University Chemistry Dept.

A sensing platform able to detect specific sequences of DNA holds the potential to fulfill many tasks of modern medical research, clinical diagnostics and forensic science.

One such example would be the use of DNA sensors in forensic samples in order to detect specific sequences able to identify body fluids such as blood and saliva.

Conventional methods for body fluid identification can be labour-intensive and require multiple steps with technologically diverse techniques. Meanwhile, a simple method able to selectively detect target sequences (RNA or DNA) specific to a body fluid would greatly aid the current market.

Fluid identification provides information about the correct storage protocol, sample handling and has the potential to identify mixtures of fluids.

Marsilea Booth is a PhD candidate, at The University of Auckland Chemistry Department, supervised by A/Prof Jadranka Travas-Sejdic and Dr. Sally Ann Harbison.

The aim of our research is to develop a sensing platform using resistive pulse sensing to detect target DNA sequences that are specific to blood. In this study, probe DNA-grafted particles are used to detect target DNA. When present in solution, target DNA selectively hybridizes to complementary probe DNA.

The qNano is  used to detect changes in particle character as the surface species go from single-stranded DNA to double-stranded DNA. So far the early stages of a proof-of-principle have been undertaken showing potential. The advantages of this method include portability, sensitivity, selectivity and particle-by-particle analysis.

Photo: Marsilea Booth (PhD Candidate, University of Auckland Chemistry Department)