Biofouling-resilient nanoporous gold electrodes for DNA sensing.
Electrochemical nucleic acid sensors are promising tools for point-of-care diagnostic platforms with their facile integration with electronics and scalability. However, nucleic acid detection in complex biological fluids is challenging as biomolecules nonspecifically adsorb on the electrode surface and adversely affect the sensor performance by obscuring the transport of analytes and redox species to the electrode. We report that nanoporous gold (np-Au) electrodes, prepared by a microfabrication-compatible self-assembly process and functionalized with DNA probes, enabled detection of target DNA molecules (10-200 nM) in physiologically relevant complex media (bovine serum albumin and fetal bovine serum). In contrast, the sensor performance was compromised for planar gold electrodes in the same conditions. Hybridization efficiency decreased by 10% for np-Au with coarser pores revealing a pore-size dependence of sensor performance in biofouling conditions. This nanostructure-dependent functionality in complex media suggests that the pores with the optimal size and geometry act as sieves for blocking the biomolecules from inhibiting the surfaces within the porous volume while allowing the transport of nucleic acid analytes and redox molecules.
Department of Electrical and Computer Engineering, University of California , Davis, California 95616, United States.
Pallavi
P
Daggumati
Department of Electrical and Computer Engineering, University of California , Davis, California 95616, United States.
Zimple
Z
Matharu
Department of Electrical and Computer Engineering, University of California , Davis, California 95616, United States.
Ling
L
Wang
Department of Electrical and Computer Engineering, University of California , Davis, California 95616, United States.
Erkin
E
Seker
D000818:Animals; D057219:Biofouling; D015374:Biosensing Techniques / Q000295:instrumentation*; D002417:Cattle; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D012710:Serum Albumin, Bovine / Q000032:analysis / Q000737:chemistry*
D012710:Serum Albumin, Bovine; D006046:Gold; D004247:DNA