Thesis defense Cansu Pinar Yenice
Sala de Graus of the ETSEQ, URV
Ms. Cansu Pinar Yenice will defend her doctoral thesis next Thursday, 21 November, 2024 at 11.00h in the Sala de Graus of the ETSEQ.
Title: "NEXT GENERATION MOLECULAR DIAGNOSTIC ELECTROCHEMICAL PLATFORMS"
Supervisors: Dr. Ciara O'Sullivan, Dr. Mayreli Ortiz
Abstract:
Electrochemical detection is particularly attractive for biosensors due to the high sensitivity, simplicity, rapid response, cost-effectiveness and simplified instrumentation as compared to that required for optical transduction, as well as its compatibility with miniaturization and low sample volumes. Although the intrinsic redox properties of all nucleobases of DNA and RNA enable the development of label-free electrochemical biosensors to provide structure-sensitive DNA analysis and/or detection analysis with the advantage of direct DNA measurement, they face limitations with regards to the choice of electrode material, lack of sensitivity or the ability to achieve regeneratable sensors. External electroactive labels have been introduced not only to overcome these limitations but also to improve the sensitivity of sensors and facilitate the use of a greater range of electrode materials. The first part of this thesis explores the use of redox labels, moving towards a final goal of achieving an approach for electrochemical DNA sequencing. Successful incorporation of five oxidizable redox labels achieved simultaneous and ratiometric electrochemical detection and the quantification of the total number of each nucleobases was achieved.
In the second part of the thesis, generic electrochemical platforms were developed for the detection of DNA, viral RNA and Single Nucleotide Polymorphisms (SNPs), taking advantage of redox labelled dNTPs and an isothermal amplification technique. Different methodologies were used for each type of target. Identification of SNP hetero/homozygosity was achieved with the combination of asymmetric isothermal recombinase polymerase amplification (RPA) and solid-phase electrochemical melting curve analysis. RNA purification free and reverse transcription free detection of RdRP, N and E genes of SARS-CoV-2 was achieved using solid phase RPA, and finally high risk HPV types were detected via solid phase bridge RPA amplification, with all approaches being validated using real samples.
