Liposomes as signal amplification reagents for bioassays in microfluidic channels

Locascio, Laurie E.; Hong, Jennifer S.; Gaitan, Michael

doi:10.1002/1522-2683(200203)23:5<799::aid-elps799>3.0.co;2-p

Cited by 26 publications

(13 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…the highly charged liposomes may ultimately be ideally suited for low analyte concentrations 45 and microfluidic testing devices. 15,29 Temperature dependency of liposome binding Binding events as well as the refractive index are strongly dependent on the temperature. 46 Therefore, the interactions between the model surface consisting of HS(CH 2 ) 11 -OH and liposomes without the N-glutaryl-DPPE tag were recorded at 25, 37 and 50 °C (Fig.…”

Section: Comparison Of Liposomes With and Without The N-glutaryl-dppe...mentioning

confidence: 99%

“…14 Despite the high performance of liposome-based sensors and drug delivery systems, the dynamics of the interactions between the utilized vesicles and their target surfaces have only been marginally studied and are still not well understood. In particular, in microfluidic devicesa growing field in (bio)analytical researchhigh surface areas are encountered that can lead to increasing non-specific adsorption 15 and need to be avoided by clever surface engineering strategies. Here, mechanistic understanding of the binding processes is crucial for the optimization of sensors as well as therapeutic applications based on liposomes, where intensive efforts in liposome engineering are made to maximize the uptake of a drug for the desired target.…”

Section: Introductionmentioning

confidence: 99%

“…We focus on this type of liposome, as it is favourably used in high-performance sensing applications 1,10 that are often combined with microfluidic sample handling. 15,29 Liposomes with negative surface charge have been shown not to rupture as easily as positively charged ones when adsorbing to solid surfaces. 30 Also, with most biological molecules bearing negative charges, non-specific binding of anionic liposomes favours their use in bioassays.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Investigating non-specific binding to chemically engineered sensor surfaces using liposomes as models

Fenzl

Genslein

Domonkos

et al. 2016

Analyst

View full text Add to dashboard Cite

Nanoparticles are ubiquitously used for signal enhancement in (bio)sensors, but their true possible performance is typically hampered by non-specific binding. A better understanding of the nature and the prevention of non-specific binding through surface engineering of the particles and sensor surfaces is needed to intelligently design (bio)sensors and potentially avoid bulk blocking methods. Hence, two types of liposomes were used as model for signal-enhancing nanoparticles. Their surface was engineered to bear negative surface charge. One type was synthesized with additional 6 mol% -COOH groups. Their interaction with four typical chemically modified sensor surfaces was then mechanistically characterized by surface plasmon resonance (SPR) spectroscopy. It was shown that the non-specific binding can be described with Langmuir isotherms providing quantitative information of dissociation constants and surface loading with especially high correlation coefficients (>0.97) for all the studied sensor surfaces modified with hydrophilic alkane thiols. By tailoring the sensor surface chemistry, non-specific binding was significantly minimized. Here, carboxyl- or methyl-terminated surfaces performed best. In fact, the pairing of -COOH groups on the sensor surface with -COOH groups on the liposomes almost completely eliminated non-specific binding, resulting in a SPR signal change of only 1 mRIU (refractive index unit) at 100 μM phospholipid concentration. Surprisingly though, -OH groups on the surface, which are also commonly used in sensing applications, did not lead to decreased adsorption, but caused significant signal changes (4 mRIU at 100 μM phospholipid) due to non-specific binding. Overall, the mechanistic studies presented here demonstrate that by careful design of the nanoparticle surface and by choosing sensor surfaces with terminal -CH3 or -COOH groups, improved sensing (micro)systems with very low non-specific adsorption can be obtained.

show abstract

Section: Comparison Of Liposomes With and Without The N-glutaryl-dppe...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Investigating non-specific binding to chemically engineered sensor surfaces using liposomes as models

Fenzl

Genslein

Domonkos

et al. 2016

Analyst

View full text Add to dashboard Cite

show abstract

“…Liposomes, sphere‐shaped vesicles, are composed of a phospholipid bilayer surrounding an aqueous core . The inner cavity of the liposomes can be used for storage of enzymes, proteins, DNA, drugs, and other substances . Research on liposome technology has progressed from conventional vesicles to second‐generation liposomes, in which long‐circulating liposomes are obtained by modulating the lipid composition, size, and charge of the vesicle.…”

Section: Introductionmentioning

confidence: 99%

Liposomal nanotransporter for targeted binding based on nucleic acid anchor system

et al. 2013

View full text Add to dashboard Cite

Microfluidic techniques have been developed intensively in recent years due to lower reagent consumption, faster analysis, and possibility of the integration of several analytical detectors into one chip. Electrochemical detectors are preferred in microfluidic systems, whereas liposomes can be used for amplification of the electrochemical signals. The aim of this study was to design a nanodevice for targeted anchoring of liposome as transport device. In this study, liposome with encapsulated Zn(II) was prepared. Further, gold nanoparticles were anchored onto the liposome surface allowing binding of thiol moiety-modified molecules (DNA). For targeted capturing of the transport device, DNA loops were used. DNA loops were represented by paramagnetic microparticles with oligo(DT)25 chain, on which a connecting DNA was bound. Capturing of transport device was subsequently done by hybridization to the loop. The individual steps were analyzed by electrochemistry and UV/Vis spectrometry. For detection of Zn(II) encapsulated in liposome, a microfluidic system was used. The study succeeded in demonstrating that liposome is suitable for the transport of Zn(II) and nucleic acids. Such transporter may be used for targeted binding using DNA anchor system.

show abstract

“…Liposomes are spherical lipid vesicles consisting of a bilayered membrane structure that can be used as carriers of different signaling tracers with high carrying capacity 11 and functionalized with various biomolecules for use in a variety of bioaffinity assays. 12 For instance, ultrasensitive optical or voltammetric immunoassays were developed earlier on the basis of liposomes containing fluorescent dyes 13 or electroactive compounds. 14 Given the enormous amplification afforded by liposomes, such 'nanocarriers' can greatly enhance the high sensitivity of ISE transducers, and hence lead to ultrasensitive potentiometric bioassays.…”

Section: Introductionmentioning

confidence: 99%

Amplified potentiometric transduction of DNA hybridization using ion-loaded liposomes

Chumbimuni‐Torres

Clawson

et al. 2010

Analyst

View full text Add to dashboard Cite

Amplified potentiometric transduction of DNA hybridization based on using liposome 'nanocarriers' loaded with the signaling ions is reported. The liposome-amplified potentiometric bioassay involved the duplex formation, followed by the capture of calcium-loaded liposomes, a surfactant-induced release and highly-sensitive measurements of the calcium signaling ions using a Ca(2+) ion-selective electrode (ISE). The high loading yield of nearly one million signaling ions per liposome leads to sub-fmol DNA detection limits. Factors affecting the ion encapsulation efficiency and signal amplification are evaluated and discussed. The influence of the surfactant lysing agent is also examined. Such use of 'green' calcium signaling ions addresses the inherent toxicity of Ag and CdS nanoparticle tags used in previous potentiometric bioassays. The new strategy was applied for the detection of low levels of E. coli bacteria. It could be readily extended to trace measurements of other important biomolecules in connection to different biorecognition events. The attractive analytical performance makes liposomes a useful addition to the armory of potentiometric bioassays.

show abstract

Liposomes as signal amplification reagents for bioassays in microfluidic channels

Cited by 26 publications

References 18 publications

Investigating non-specific binding to chemically engineered sensor surfaces using liposomes as models

Investigating non-specific binding to chemically engineered sensor surfaces using liposomes as models

Liposomal nanotransporter for targeted binding based on nucleic acid anchor system

Amplified potentiometric transduction of DNA hybridization using ion-loaded liposomes

Contact Info

Product

Resources

About