A low cost thin-film transistor (TFT) nanoribbon (NR) sensor has been developed for rapid real-time detection of DNA amplification using an isothermal Recombinase Polymerase Amplification (RPA) method. The semiconductor chip measures DNA amplification through a pH change, rather than via fluorescence. The utility of the method was demonstrated by amplifying CTX-M and NDM, two genes that confer bacterial resistance to cephalosporins and carbapenems, respectively. It is shown that this approach provides extremely fast and sensitive detection. It can detect <10 copies of the gene in genomic DNA extracted from E. coli or K. pneumoniae clinical isolates within a few minutes. A differential readout system was developed to minimize the effect of primer-dimer amplification on the assay. The simple device has the potential for low cost, portable and real-time nucleic acid analysis as a Point of Care device.
Bibliographical noteFunding Information:
The authors would like to acknowledge the Technology Strategy Board (TSB) and the Engineering and Physical Sciences Research Council (EPSRC, Grant EP/K502327/1) for funding this work. We would like to thank Sally Anderson, Gregory Gay, Ben Hadwen, Chris J. Brown, and Jonathan Buse of Sharp Laboratories Europe for many useful discussions and development of a measurement jig. We also thank TwistDX for providing information on the RPA reaction. The authors would also like to thank Martha Valiadi for useful discussions. All data supporting this study are openly available from the University of Southampton repository at http://doi.org/10.5258/SOTON/404101.
© 2017 The Authors
- Antimicrobial resistance (AMR)
- Isothermal nucleic acid amplification
- Recombinase Polymerase Amplification (RPA)
- Thin Film Transistor (TFT)