Miniaturized devices have had a significant impact on our society in revolutionizing the electronics industry. A similar trend of size-reduction is emerging in the health care industry to produce small bioanalytical devices for disease diagnosis, novel methods for drug delivery to treat diseases, and microfabricated platforms for studying microorganisms. Nanostructured materials, in particular, offer tremendous opportunities for engineering advanced device components for diagnostic and therapeutic applications. Despite the recent research on these materials, significant challenges remain in controlling material properties, interfacing nanocomponents with instrumentation, and engineering their interaction with biological systems.


The overarching objective of our group is to utilize our expertise at the intersection of nanostructured materials development, microfluidics, and device engineering to overcome challenges in the evolution of miniaturized devices relevant to microelectronics and life sciences. We gratefully acknowledge support from National Science Foundation (1512745 & 1454426), UC Lab Fees Research Program (12-LR-237197), NIH Biotechnology Training Program (T32-GM008799), and UC Davis Research Investments in the Sciences and Engineering (RISE).


The projects listed below are a selected group of our current research thrusts. Please contact Prof. Erkin Şeker for more information.


Current Projects


Nanoporous Metal Synthesis and Characterization

Nanoporous metals, with their highly-tunable properties, are promising candidates for multifunctional device coatings1,2. In order to develop application-specific nanoporous metals, it is imperative to have a thorough understanding of material properties at multiple levels, including electrical, thermo-mechanical, and interfacial. Previously, we engineered micro-beam arrays to probe thermo-mechanical properties3, studied fluid transport in nanoporous thin films4, and synthesized highly-flexible conductive composites5.


Currently, we are creating on-chip libraries of application-specific nanoporous metals as high-throughput characterization tools6-8. These libraries will allow for combinatorial studies of structure-property relationships in the context of biomolecule-tissue-material interactions.


Freestanding nanoporous gold beam array



Nanostructured Electrochemical Biosensors

An integral component of biosensor platforms with an electrochemical read-out is the sensor element that interfaces biomolecular detection probes with instrumentation electronics. Sensor performance, on both biomolecular and electrical levels, is strongly influenced by sensor coating properties, such as morphology, surface chemistry, and metallurgy9. While nanostructured materials have shown significant promise in enhancing the performance of these sensors, the underlying mechanisms for this enhancement are not fully understood.


Currently, we are fabricating novel nanostructured electrodes to understand how nanoscale features enhance sensitive measurement of nucleic acids10,11. The fundamental studies will reveal a set of design rules for the development of nanostructured electrochemical sensor elements and assist technological advancements in food safety, water quality, and medical diagnostics.


Tunable nanoporous gold morphology



Engineering Tissue-Material Interaction

Tissue response is due in part to a complex set of cues, including soluble factors, surface chemistry, and topography. A widely accepted hypothesis is that the right combination of cues from a biomedical device coating will increase device efficacy and safety. A critical step in understanding tissue response is to identify the relationship between material properties, biomolecule-surface interactions12, and biological responses13.


Currently, we are combining nanoporous metal technology and microfluidic platforms14,15 to create large-scale material-tissue interrogation arrays. These microfabricated platforms will enable the systematic study of material-biomolecule-tissue interactions and help us in identifying optimal attributes for device coatings that maximize the desired biological response.


Astrocyte adhering onto porous surface



Creating Translational Biomedical Devices

The scarcity of medical devices that can both detect physiological activity and stimulate it impose a significant obstacle to effective therapeutics. This is particularly important in neurological disorders, since neurons exhibit both electrical and chemical activity as a part of their normal function. Previously, we demonstrated that nanoporous gold coatings increase the sensitivity of multiple electrode arrays in detecting neural electrical activity from brain tissue16.


Currently, we are applying the recent progress in fundamental science and technology from the earlier thrust areas to create multifunctional neural electrodes that incorporate in situ drug delivery17-19 and topographical cues13 to promote neuron-electrode coupling and to reduce astrocyte reactivity. We expect that these efforts will translate into technologies for closed-loop control of neurological disorders such as epilepsy.

Hippocampus slice on multiple electrode array


Reference Papers


1    Seker, E., Reed, M. & Begley, M. Nanoporous Gold: Fabrication, Characterization, and Applications. Materials 2:2188 (2009).

2    Daggumati, P., Kurtulus, O., Chapman, C. A. R., Dimlioglu, D. & Seker, E. Microfabrication of Nanoporous Gold Patterns for Cell-material Interaction Studies. Journal of Visual Experiments 77:e50678 (2013).

3    Seker, E., Gaskins, J., Bart-Smith, H., Zhu, J., Reed, M., Zangari, G., Kelly, R. & Begley, M. The effects of post-fabrication annealing on the mechanical properties of freestanding nanoporous gold structures. Acta Materialia 55:4593 (2007).

4    Seker, E., Begley, M., Reed, M. & Utz, M. Kinetics of capillary wetting in nanoporous films in the presence of surface evaporation. Applied Physics Letters 92:013128 (2008).

5    Seker, E., Reed, M., Utz, M. & Begley, M. Flexible and conductive bilayer membranes of nanoporous gold and silicone: Synthesis and characterization. Applied Physics Letters 92:154101 (2008).

6    Dorofeeva, T. S. & Seker, E. Electrically tunable pore morphology in nanoporous gold thin films. Nano Research 8:2188 (2015).

7    Chapman, C. A., Daggumati, P., Gott, S. C., Rao, M. P. & Seker, E. Substrate topography guides pore morphology evolution in nanoporous gold thin films. Scripta Materialia 110:33 (2016).

8    Chapman, C. A., Wang, L., Biener, J., Seker, E., Biener, M. M. & Matthews, M. J. Engineering on-chip nanoporous gold material libraries via precision photothermal treatment. Nanoscale 8:785 (2016).

9    Zhou, J. C., Feller, B., Hinsberg, B., Sethi, G., Feldstein, P., Hihath, J., Seker, E., Marco, M., Knoesen, A. & Miller, R. Immobilization-mediated reduction in melting temperatures of DNA–DNA and DNA–RNA hybrids: Immobilized DNA probe hybridization studied by SPR. Colloids and Surfaces A: Physicochemical and Engineering Aspects 481:72 (2015).

10  Daggumati, P., Matharu, Z. & Seker, E. Effect of Nanoporous Gold Thin Film Morphology on Electrochemical DNA Sensing. Analytical Chemistry 87:8149 (2015).

11  Daggumati, P., Matharu, Z., Wang, L. & Seker, E. Biofouling-resilient nanoporous gold electrodes for DNA sensing. Analytical Chemistry 87:8618 (2015).

12  Huang, L., Seker, E., Landers, J., Begley, M. & Utz, M. Molecular Interactions in Surface-Assembled Monolayers of Short Double-Stranded DNA. Langmuir 26:11574 (2010).

13  Chapman, C. A., Chen, H., Stamou, M., Biener, J., Biener, M. M., Lein, P. J. & Seker, E. Nanoporous Gold as a Neural Interface Coating: Effects of Topography, Surface Chemistry, and Feature Size. ACS Applied Materials and Interfaces 7:7093 (2015).

14  Leslie, D., Easley, C., Seker, E., Karlinsey, J., Utz, M., Begley, M. & Landers, J. Frequency-specific flow control in microfluidic circuits with passive elastomeric features. Nature Physics 5:231 (2009).

15  Seker, E., Leslie, D., Haj-Hariri, H., Landers, J., Utz, M. & Begley, M. Nonlinear pressure-flow relationships for passive microfluidic valves. Lab on a Chip 9:2691 (2009).

16  Seker, E., Berdichevsky, Y., Begley, M., Reed, M., Staley, K. & Yarmush, M. The fabrication of low-impedance nanoporous gold multiple-electrode arrays for neural electrophysiology studies. Nanotechnology 21:125504 (2010).

17  Seker, E., Berdichevsky, Y., Staley, K. J. & Yarmush, M. L. Microfabrication-Compatible Nanoporous Gold Foams as Biomaterials for Drug Delivery. Advanced Healthcare Materials 1:172 (2012).

18  Kurtulus, O., Daggumati, P. & Seker, E. Molecular Release from Patterned Nanoporous Gold Thin Films. Nanoscale 6:7062 (2014).

19  Polat, O. & Seker, E. Halide-Gated Molecular Release from Nanoporous Gold Thin Films. The Journal of Physical Chemistry C 119:24812 (2015).