Abstract
A flow-through sensing platform based on open-ended porous silicon (PSi) microcavity membranes that are compatible with integration in onchip sensor arrays is demonstrated. Because of the high aspect ratio of PSi nanopores, the performance of closed-ended PSi sensors is limited by infiltration challenges and slow sensor responses when detecting large molecules such as proteins and nucleic acids. In order to improve molecule transport efficiency and reduce sensor response time, open-ended PSi nanopore membranes were used in a flow-through sensing scheme, allowing analyte solutions to pass through the nanopores. The molecular binding kinetics in these PSi membranes were compared through experiments and simulation with those from closed-ended PSi films of comparable thickness in a conventional flow-over sensing scheme. The flow-through PSi membrane resulted in a 6-fold improvement in sensor response time when detecting a high molecular weight analyte (streptavidin) versus in the flow-over PSi approach. This work demonstrates the possibility of integrating multiple flow-through PSi sensor membranes within parallel microarrays for rapid and multiplexed label-free biosensing.
Original language | English |
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Pages (from-to) | 10940-10948 |
Number of pages | 9 |
Journal | Analytical Chemistry |
Volume | 88 |
Issue number | 22 |
DOIs | |
State | Published - Nov 15 2016 |
Funding
This work was supported in part by the Army Research Office (Grants W911NF-15-1-0176 and W911NF-09-1-0101). Photolithography was conducted at the Center for Nanophase Materials Sciences (CNMS) at Oak Ridge National Laboratory, which is a DOE Office of Science User Facility. Equipment and technical support at the Vanderbilt Institute for Nanoscale Science and Engineering (VINSE) and Vanderbilt Institute for Integrative Biosystems Research and Education (VIIBRE) were also utilized for this work. The authors gratefully acknowledge D. S. Koktysh for supplying quantum dots, D. P. Briggs for assistance with sample fabrication, C. L. Pint and K. Share for facilitating wafer-scale PSi etching, and G. A. Rodriguez, K. Qin, and S. Hu for useful technical discussions.