An experimental setup has been constructed for simultaneous measurements of the frequency, absolute Q factor, and amplitude oscillation a quartz crystal microbalance (QCM). The technical solution allows operation in vacuum, air, or liquid. is driven at its resonant frequency by an oscillator that can be intermittently disconnected causing to decay exponentially. From recorded curve factor (calculated from time constant), freely oscillating crystal, are obtained. All fully automated. One...

We have measured the time-resolved adsorption kinetics of mussel adhesive protein (Mefp-1) on a nonpolar, methyl-terminated (thiolated) gold surface, using three independent techniques: quartz crystal microbalance with dissipation monitoring (QCM-D), surface plasmon resonance, and ellipsometry. The QCM-D ellipsometry data shows that, after to saturation Mefp-1, cross-linking layer NaIO4 transforms it from an extended (∼20 nm), water-rich, hydrogel-like state much thinner (∼5 compact, less...

We have measured the energy dissipation of quartz crystal microbalance(QCM), operating in liquid phase, when mono- or multi-layers bio-molecules and biofilms form on QCM electrode (with a time resolution ca. 1 s). Examples are taken from protein adsorption, lipid vesicle adsorption cell adhesion studies. Our results show that even very thin (a few nm) dissipate significant amount owing to oscillation. Various mechanisms for this discussed. Three main contributions increase considered. (i) A...

A new quartz crystal microbalance instrument, allowing simultaneous frequency (f) and dissipation factor (D) measurements, has been used to study protein adsorption kinetics by measuring time-resolved data of both the D-factor, energy due added overlayer, f-shift, effective mass load on sensor. Four model proteins (myoglobin, hemoglobin, human serum albumin (HSA), ferritin) one antibody−antigen reaction (antibody against HSA) were studied a hydrophobic, methyl-terminated (−CH3) gold surface....

The adsorption kinetics of small unilamellar egg-yolk phosphatidylcholine vesicles was investigated by the quartz crystal microbalance−dissipation (QCM−D) technique, as a function surface chemistry (on SiO2, Si3N4, Au, TiO2, and Pt), temperature (273−303 K), vesicle size (25−200 nm), osmotic pressure. On SiO2 adsorb intact at low coverage, followed transformation to bilayer critical coverage. oxidized Pt, all coverages studied temperatures. Variation does not change qualitative behavior on...

We have studied the adsorption of two structurally similar forms hemoglobin (met-Hb and HbCO) to a hydrophobic self-assembled methyl-terminated thiol monolayer on gold surface, by using Quartz Crystal Microbalance (QCM) technique. This technique allows time-resolved simultaneous measurements changes in frequency ( f ) (c.f. mass) energy dissipation (D) rigidity/viscoelastic properties) QCM during process, which makes it possible investigate viscoelastic properties different protein layers...

The colorimetric variations induced upon changes in interfacial refractive index of nanoscale noble metal structures exhibiting localized surface plasmon resonance (LSPR) provides a convenient means label-free, affinity-based detection biomolecular recognition reactions. However, despite being similar nature to conventional SPR, LSPR has so far suffered from significantly lower data quality terms its signal-to-noise ratio (S/N) typical analysis. In this work, generic analysis algorithms and...

We report the use of individual gold nanorods as plasmonic transducers to detect binding streptavidin biotin-conjugated in real time on a surface. Label-free detection at single-nanorod level was performed by tracking wavelength shift nanorod-localized surface plasmon resonant scattering spectrum using dark-field microspectroscopy system. The lowest concentration that experimentally measured 1 nM, which is factor 1000-fold lower than previously reported limit for biotinylated single...

Recently, several reports have shown that when one side of a quartz crystal microbalance (QCM) is exposed to liquid, the parallel (but not series) resonant frequency influenced by conductivity and dielectric constant liquid. The effect still controversial constitutes serious complication in many applications QCM liquid environments. One suggestion has been acoustically induced surface charges couple charged species conducting To explore this effect, we measured series mode resonance...

Simultaneous quartz crystal microbalance with dissipation monitoring (QCM-D) and surface plasmon resonance (SPR) measurements are used to analyze the kinetics of two biomacromolecular systems, one lipid protein based, undergoing surface-induced conformational changes. First we establish a theoretical platform, which allows quantitative analysis combined SPR QCM-D data. With this base, new information can be extracted, not obtainable either technique alone. As an example demonstrate how...

We show how the water content (and effective density) of thin adsorbed films composed biomolecules can be determined using combined quartz crystal microbalance with dissipation monitoring (QCM-D) and surface plasmon resonance (SPR) analysis. In particular, these techniques, theoretical treatment a Voigt-based viscoelastic model, were applied to analyze state immobilized single stranded biotin-modified probe DNA (b-DNA) coupled via streptavidin biotin-doped supported phospholipid bilayer...

In nature, the fusion of phospholipid vesicles is regulated and catalyzed by highly specialized SNARE proteins. A key step in this process to bring about close apposition lipid bilayers that are destined fuse. Inspired nature's use molecular recognition between receptor proteins, we developed a method force into proximity selective hybridization membrane-anchored DNA strands. We demonstrate forced bilayer contact triggers vesicle fusion.

Supported phospholipid bilayers (SPBs) have emerged as important model systems for studies of the natural cell membrane and its components, which are essential integrity function cells in all living organisms, also constitute common targets therapeutic drugs disease diagnosis. However, preferential occurrence spontaneous SPB formation on silicon-based substrates, but not bare noble-metal surfaces, has so far excluded use localized surface plasmon resonance (LSPR) sensing principle...

Kinetics of vesicle adsorption on SiO2 and TiO2 surfaces was investigated for sizes from 25 to 200 nm. On SiO2, nonruptured vesicles are adsorbed up a critical coverage, Θc, after which spontaneous rupture bilayer formation occurs in qualitatively the same manner all sizes. TiO2, continues saturation. A comparison between kinetics at low coverages where intact adsorb both surfaces, reveals that more flattened than indicating stronger vesicle-surface interaction SiO2.

By mimicking Nature's way of utilizing multivalent interactions, we introduce in the present work a novel method to improve strength cholesterol-based DNA coupling lipid membranes. The bivalent was accomplished by hybridization between 15-mer and 30-mer DNA, being modified with cholesterol 3' 5' end, respectively. Compared one moiety only, binding membranes appears be significantly stronger even irreversible over time scale investigated ( approximately 1 hr). First, this means that can used...

The optical response of isolated holes in 20 nm thin gold is probed as a function alkanethiol CH(3)(CH2)x SH (x epsilon 1-15) and protein adsorption using dark-field spectroscopy. We establish that the plasmon excitations single short-range ordered 60 exhibit similar E-field decay lengths delta approximately 10-20 hole can be used to resolve successive (biotin-BSA) its interaction partner (neutravidin). data confirm localized character demonstrate applicability for bio/chemosensing particle plasmons.

We have used a new setup for parallel quartz crystal microbalance with dissipation (QCM-D) and surface plasmon resonance (SPR) measurements to measure the detailed kinetics of vesicle-to-bilayer transformation on SiO2 vesicle adsorption Au, respectively. The combination SPR QCM-D, complemented by atomic force microscopy measurements, has enabled complete, time-resolved separation bilayer coverages, thus, first time, allowed precise quantification critical coverage vesicles needed rupture....

We report here how the quartz crystal microbalance with dissipation monitoring (QCM-D) technique, simultaneously measuring changes in induced energy dissipation, D (cf. viscoelastic properties), and frequency, f coupled mass), can be used to characterize bound state of single-stranded peptide nucleic acid (PNA) deoxyribose (DNA) relation their ability function as selective probe(s) for fully complementary single-mismatch DNA. The possibility use QCM-D technique detection binding kinetics...

We present a new grafting-to method for resistant "non-fouling" poly(ethylene glycol) brushes, which is based on grafting of polymers with reactive end groups in 0.9 M Na2SO4 at room temperature. The process, the resulting and resistance toward biomolecular adsorption are investigated by surface plasmon resonance, quartz crystal microbalance, atomic force microscopy. determine both density thickness independently use narrow molecular weight distributions result well-defined brushes. High...

We show that aligned gold nanotube arrays capable of supporting plasmonic resonances can be used as high performance refractive index sensors in biomolecular binding reactions. A methodology to examine the sensing ability inside and outside walls structures is presented. The sensitivity nanotubes found increase are exposed, characteristic shown different. Finite element simulations showed good qualitative agreement with observed behavior. Free standing displayed bulk sensitivities region 250...

This paper presents the use of localized surface plasmon resonance (LSPR) sensor concept to probe formation macroscopic and laterally mobile supported lipid bilayers (SLBs) on SiOx-encapsulated nanohole-containing Au Ag films. A comparison between Au- Ag-based templates demonstrates a higher sensitivity for Au-based with respect both bulk interfacial refractive index (RI) changes in aqueous solution. The lateral mobility SLBs formed nanohole was analyzed using fluorescence recovery after...