Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 6, Issue 15, Pages 12618-12628Publisher
AMER CHEMICAL SOC
DOI: 10.1021/am502613x
Keywords
archaeal bipolar tetraether lipids; free-standing planar membranes; fluidics; PDMS film; electrochemical impedance spectroscopy
Funding
- National Science Foundation [CMMI-1141815, CMMI-1141830, CMMI-1266306, DMR-1105277]
- Centralized Research Facilities at Drexel University
- Direct For Mathematical & Physical Scien
- Division Of Materials Research [1105277] Funding Source: National Science Foundation
- Directorate For Engineering
- Div Of Civil, Mechanical, & Manufact Inn [1266338] Funding Source: National Science Foundation
- Div Of Chem, Bioeng, Env, & Transp Sys
- Directorate For Engineering [1438025] Funding Source: National Science Foundation
- Div Of Civil, Mechanical, & Manufact Inn
- Directorate For Engineering [1266306] Funding Source: National Science Foundation
Ask authors/readers for more resources
The polar lipid fraction E (PLFE) isolated from the thermoacidophilic archaeon Szilfolobus acidocaldarius contains exclusively bipolar tetraether lipids, which are able to form extraordinarily stable vesicular membranes against a number of chemical, physical, and mechanical stressors. PLFE liposomes have thus been considered appealing biomaterials holding great promise for biotechnology applications such as drug delivery and biosensing. Here we demonstrated that PLFE can also form free-standing planar membranes on micropores (similar to 100 mu m) of polydimethylsiloxane (PDMS) thin films embedded in printed circuit board (PCB)-based fluidics. To build this device, two novel approaches were employed: (i) an S1813 sacrificial layer was used to facilitate the fabrication of the PDMS thin film, and (ii) oxygen plasma treatment was utilized to conveniently bond the PDMS thin film to the PCB board and the PDMS fluidic chamber. Using electrochemical impedance spectroscopy, we found that the dielectric properties of PLFE planar membranes suspended on the PDMS films are distinctly different from those obtained from diester lipid and triblock copolymer membranes. In addition to resistance (R) and capacitance (C) that were commonly seen in all the membranes examined, PLFE planar membranes showed an inductance (L) component. Furthermore, PLFE planar membranes displayed a relatively large membrane resistance, suggesting that, among the membranes examined, PLFE planar membrane would be a better matrix for studying channel proteins and transmembrane events. PLFE planar membranes also exhibited a sharp decrease in phase angle with the frequency of the input AC signal at similar to 1 MHz, which could be utilized to develop sensors for monitoring PLFE membrane integrity in fluidics. Since the stability of free-standing planar lipid membranes increases with increasing membrane packing tightness and PLFE lipid membranes are more tightly packed than those made of diester lipids, PLFE free-standing planar membranes are expected to be considerably stable. All these salient features make PLFE planar membranes particularly attractive for model studies of channel proteins and transmembrane events and for high-throughput drug screening and artificial photosynthesis. This work can be extended to nanopores of PDMS thin films in microfluidics and eventually aid in membrane-based new lab-on-a-chip applications.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available