Biomimetic membrane rafts stably supported on unmodified gold

Marquês, Joaquim T.; Almeida, Rodrigo F.M. de; Viana, Ana S.

doi:10.1039/c2sm06738b

Cited by 29 publications

(52 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2b). Also, by ellipsometry, a thickness of ∼5.2 nm was estimated for the SLB, which is in good agreement with the one expected [29]. Moreover, ellipsometry also shows that only a negligible amount of IgG adsorbed on the SLB (Table 1).…”

Section: Resultssupporting

confidence: 87%

“…In fact, the lipid film thickness estimated was 5.5 nm (Table 1), in excellent agreement with the values previously obtained by us for gold-supported lipid bilayers [5,29]. It also matches the data reported for a liquid ordered phase of DPPC/Chol [37,38].…”

Section: Immunosensing Interface On Decanethiol-containing Lipid Membsupporting

confidence: 91%

“…The thickness of the lipid film was estimated as reported in the literature [5,27] fixing the real part of the refractive index at 1.5 [29,30]. The very low extinction coefficient values (k) obtained in this work ranged from 0.03 to 0.11, which indicates nearly transparent films, as expected for thin organic layers [27].…”

Section: Ellipsometrysupporting

confidence: 61%

“…Performance of SLB (DPPC/Chol. 70:30 mol%) deposited onto a MUA SAM as a sensing interface A lipid bilayer was deposited on gold surfaces modified with MUA, the SAM typically used for these purposes [5,29,31], and its ability to prevent the nonspecific adsorption of BSA and IgG was tested. MUA SAM alone, as expected, did not prevent nonspecific adsorption of IgG (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Subsequently, they were hydrated with Hepes buffer to a final concentration of 1 mM. The large unilamellar vesicles (LUV) suspension was prepared as previously reported [29], by the extrusion method using polycarbonate filters with 400 nm diameter pores (Nuclepore, Whatman).…”

Section: Preparation Of Vesiclesmentioning

confidence: 99%

See 4 more Smart Citations

Phospholipid/cholesterol/decanethiol mixtures for direct assembly of immunosensing interfaces

Almeida

Marquês

Liu

et al. 2015

Colloids and Surfaces B: Biointerfaces

View full text Add to dashboard Cite

a b s t r a c tIn this work, a simple yet robust method to prepare lipid-based biosensing interfaces on gold using common lipids (a phospholipid and cholesterol) and an alkanethiol is reported. The lipids were carefully chosen to tailor the biophysical properties of the bilayer. The simplicity of the method relies on the incorporation of a small percentage of decanethiol in the lipid vesicles for a direct formation of a thiol-linked supported lipid bilayer, which is advantageous in several respects. It prevents the use of specially synthesized thiolipids and preserves the natural fluidity and dynamics of the lipids. As a consequence the whole arrangement is extremely stable regarding ionic strength changes and solution flow during surface plasmon resonance experiments. Moreover, we show that this interface is very effective on suppressing the nonspecific adsorption of proteins on the surface, and enables the covalent attachment of the recognition antibody. The subsequent detection of specific interaction toward antigen was monitored in real-time by SPR and confirmed by ellipsometric measurements. This lipid-based biosensing platform is versatile and can be adapted to the biorecognition reaction of interest.

show abstract

Section: Resultssupporting

confidence: 87%

Section: Immunosensing Interface On Decanethiol-containing Lipid Membsupporting

confidence: 91%

Section: Ellipsometrysupporting

confidence: 61%

Section: Resultsmentioning

confidence: 99%

Section: Preparation Of Vesiclesmentioning

confidence: 99%

See 3 more Smart Citations

Phospholipid/cholesterol/decanethiol mixtures for direct assembly of immunosensing interfaces

Almeida

Marquês

Liu

et al. 2015

Colloids and Surfaces B: Biointerfaces

View full text Add to dashboard Cite

show abstract

A reusable device for electrochemical applications of hydrogel supported black lipid membranes

Mech-Dorosz

Heiskanen

Bäckström

et al. 2015

Biomed Microdevices

View full text Add to dashboard Cite

Black lipid membranes (BLMs) are significant in studies of membrane transport, incorporated proteins/ion transporters, and hence in construction of biosensor devices. Although BLMs provide an accepted mimic of cellular membranes, they are inherently fragile. Techniques are developed to stabilize them, such as hydrogel supports. In this paper, we present a reusable device for studies on hydrogel supported (hs) BLMs. These are formed across an ethylene tetrafluoroethylene (ETFE) aperture array supported by the hydrogel, which is during in situ polymerization covalently "sandwiched" between the ETFE substrate and a gold electrode microchip, thus allowing direct electrochemical studies with the integrated working electrodes. Using electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy and contact angle measurements, we demonstrate the optimized chemical modifications of the gold electrode microchips and plasma modification of the ETFE aperture arrays facilitating covalent "sandwiching" of the hydrogel. Both fluorescence microscopy and EIS were used to demonstrate the induced spontaneous thinning of a deposited lipid solution, leading to formation of stabilized hsBLMs on average in 10 min. The determined specific membrane capacitance and resistance were shown to vary in the range 0.31-0.49 μF/cm(2) and 45-65 kΩ cm(2), respectively, corresponding to partially solvent containing BLMs with an average life time of 60-80 min. The characterized hsBLM formation and devised equivalent circuit models lead to a schematic model to illustrate lipid molecule distribution in hydrogel-supported apertures. The functionality of stabilized hsBLMs and detection sensitivity of the platform were verified by monitoring the effect of the ion transporter valinomycin.

show abstract