Label-free high-sensitivity (bio)sensing with silicon structures and systems at the micro and nanoscale

AbstractLateral flow assays (LFAs) are the best-performing and best-known point-of-care tests worldwide. Over the last decade, they have experienced an increasing interest by researchers towards improving their analytical performance while maintaining their robust assay platform. Commercially, visual and optical detection strategies dominate, but it is especially the research on integrating electrochemical (EC) approaches that may have a chance to significantly improve an LFA’s performance that is needed in order to detect analytes reliably at lower concentrations than currently possible. In fact, EC-LFAs offer advantages in terms of quantitative determination, low-cost, high sensitivity, and even simple, label-free strategies. Here, the various configurations of EC-LFAs published are summarized and critically evaluated. In short, most of them rely on applying conventional transducers, e.g., screen-printed electrode, to ensure reliability of the assay, and additional advances are afforded by the beneficial features of nanomaterials. It is predicted that these will be further implemented in EC-LFAs as high-performance transducers. Considering the low cost of point-of-care devices, it becomes even more important to also identify strategies that efficiently integrate nanomaterials into EC-LFAs in a high-throughput manner while maintaining their favorable analytical performance.

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Microfluidics-Based Plasmonic Biosensing System Based on Patterned Plasmonic Nanostructure Arrays

Micromachines ◽

10.3390/mi12070826 ◽

2021 ◽

Vol 12 (7) ◽

pp. 826

Author(s):

Yanting Liu ◽

Xuming Zhang

Keyword(s):

Plasmon Resonance ◽

Point Of Care ◽

Simultaneous Detection ◽

High Sensitivity ◽

Microfluidic Chips ◽

Label Free ◽

Plasmonic Nanostructure ◽

Point Of Care Diagnostics ◽

Surface Enhanced Raman ◽

Nanostructure Arrays

This review aims to summarize the recent advances and progress of plasmonic biosensors based on patterned plasmonic nanostructure arrays that are integrated with microfluidic chips for various biomedical detection applications. The plasmonic biosensors have made rapid progress in miniaturization sensors with greatly enhanced performance through the continuous advances in plasmon resonance techniques such as surface plasmon resonance (SPR) and localized SPR (LSPR)-based refractive index sensing, SPR imaging (SPRi), and surface-enhanced Raman scattering (SERS). Meanwhile, microfluidic integration promotes multiplexing opportunities for the plasmonic biosensors in the simultaneous detection of multiple analytes. Particularly, different types of microfluidic-integrated plasmonic biosensor systems based on versatile patterned plasmonic nanostructured arrays were reviewed comprehensively, including their methods and relevant typical works. The microfluidics-based plasmonic biosensors provide a high-throughput platform for the biochemical molecular analysis with the advantages such as ultra-high sensitivity, label-free, and real time performance; thus, they continue to benefit the existing and emerging applications of biomedical studies, chemical analyses, and point-of-care diagnostics.

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Capacitive Field-effect (bio-)chemical Sensors Based on Nanocrystalline Diamond Films

MRS Proceedings ◽

10.1557/proc-1203-j17-31 ◽

2009 ◽

Vol 1203 ◽

Author(s):

Matthias Bäcker ◽

Arshak Poghossian ◽

Maryam H. Abouzar ◽

Sylvia Wenmackers ◽

Stoffel D. Janssens ◽

...

Keyword(s):

Thin Films ◽

Field Effect ◽

High Sensitivity ◽

Ph Sensitive ◽

Nanocrystalline Diamond ◽

Penicillin G ◽

Layer By Layer ◽

Label Free ◽

High Coverage ◽

Layer Adsorption

AbstractCapacitive field-effect electrolyte-diamond-insulator-semiconductor (EDIS) structures with O-terminated nanocrystalline diamond (NCD) as sensitive gate material have been realized and investigated for the detection of pH, penicillin concentration, and layer-by-layer adsorption of polyelectrolytes. The surface oxidizing procedure of NCD thin films as well as the seeding and NCD growth process on a Si-SiO2 substrate have been improved to provide high pH-sensitive, non-porous thin films without damage of the underlying SiO2 layer and with a high coverage of O-terminated sites. The NCD surface topography, roughness, and coverage of the surface groups have been characterized by SEM, AFM and XPS methods. The EDIS sensors with O-terminated NCD film treated in oxidizing boiling mixture for 45 min show a pH sensitivity of about 50 mV/pH. The pH-sensitive properties of the NCD have been used to develop an EDIS-based penicillin biosensor with high sensitivity (65-70 mV/decade in the concentration range of 0.25-2.5 mM penicillin G) and low detection limit (5 μM). The results of label-free electrical detection of layer-by-layer adsorption of charged polyelectrolytes are presented, too.

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High sensitivity and high Q-factor nanoslotted parallel quadrabeam photonic crystal cavity for real-time and label-free sensing

Applied Physics Letters ◽

10.1063/1.4867254 ◽

2014 ◽

Vol 105 (6) ◽

pp. 063118 ◽

Cited By ~ 77

Author(s):

Daquan Yang ◽

Shota Kita ◽

Feng Liang ◽

Cheng Wang ◽

Huiping Tian ◽

...

Keyword(s):

Photonic Crystal ◽

Real Time ◽

High Sensitivity ◽

Q Factor ◽

Label Free ◽

Photonic Crystal Cavity ◽

High Q

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TOWARDS SENSING SINGLE OR A FEW BIO-MOLECULAR ARCHITECTURES: DESIGN OF FUNCTIONAL SURFACES

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156408005266 ◽

2008 ◽

Vol 18 (01) ◽

pp. 187-194

Author(s):

PEIJI ZHAO ◽

DWIGHT WOOLARD ◽

JORGE M. SEMINARIO ◽

ROBERT TREW

Keyword(s):

Density Functional ◽

High Sensitivity ◽

Lower Sensitivity ◽

Label Free ◽

Dna Molecules ◽

Surface Attachment ◽

Biomolecular Sensing ◽

Aromatic Molecules ◽

Electrical Sensing ◽

Silicon Based

There is considerable interest in electrical sensing of biomolecular binding since it has the potential to be label free, to work easily in aqueous environments native to the biomolecules, and to be integrated with small, fast, and inexpensive microelectronoics as detection instrumentation. Although electrochemical methods have been used successfully in detections of DNA molecules with Ag labels at very high sensitivity (~ p ml), detection of DNA molecules in terms of label free techniques has a lower sensitivity (~ μ ml). Here, the surface attachment chemistry is critical towards the detection of ultra-low concentration of biomolecules. In this article, based on density functional theory, we have calculated and analyzed the electrical characteristics of the contact between aromatic molecules and silicon (100) − 2×1 surfaces. Design principles for silicon based electrodes of electrochemically biomolecular sensing instruments for label-free sensing of single or a few biomolecular molecules have also been discussed.

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Photonic crystals: A platform for label-free and enhanced fluorescence biomolecular and cellular assays

MRS Proceedings ◽

10.1557/proc-1133-aa04-01 ◽

2008 ◽

Vol 1133 ◽

Author(s):

Brian T. Cunningham ◽

Leo Chan ◽

Patrick C. Mathias ◽

Nikhil Ganesh ◽

Sherine George ◽

...

Keyword(s):

Photonic Crystal ◽

Photonic Crystals ◽

High Throughput Screening ◽

High Sensitivity ◽

Excitation Wavelength ◽

Label Free ◽

Crystal Surfaces ◽

Enhanced Fluorescence ◽

Preferred Direction ◽

Label Free Detection

Abstract Photonic crystal surfaces represent a class of resonant optical structures that are capable of supporting high intensity electromagnetic standing waves with near-field and far-field properties that can be exploited for high sensitivity detection of biomolecules and cells. While modulation of the resonant wavelength of a photonic crystal by the dielectric permittivity of adsorbed biomaterials enables label-free detection, the resonance can also be tuned to coincide with the excitation wavelength of common fluorescent tags - including organic molecules and semiconductor quantum dots. Photonic crystals are also capable of efficiently channeling fluorescent emission into a preferred direction for enhanced extraction efficiency. Photonic crystals can be designed to support multiple resonant modes that can perform label free detection, enhanced fluorescence excitation, and enhanced fluorescence extraction simultaneously on the same device. Because photonic crystal surfaces may be inexpensively produced over large surface areas by nanoreplica molding processes, they can be incorporated into disposable labware for applications such as pharmaceutical high throughput screening. In this talk, the optical properties of surface photonic crystals will be reviewed and several applications will be described, including results from screening a 200,000-member chemical compound library for inhibitors of protein-DNA interactions, gene expression microarrays, and high sensitivity of protein biomarkers.

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Label-free DNA detection based on oligonucleotide-stabilized silver nanoclusters and exonuclease III-catalyzed target recycling amplification

Analytical Methods ◽

10.1039/c4ay00838c ◽

2014 ◽

Vol 6 (15) ◽

pp. 6082-6087 ◽

Cited By ~ 6

Author(s):

Hui Ma ◽

Wei Wei ◽

Qian Lu ◽

Zhixin Zhou ◽

Henan Li ◽

...

Keyword(s):

High Sensitivity ◽

Silver Nanoclusters ◽

Label Free ◽

Exonuclease Iii ◽

Target Recycling ◽

Free Dna ◽

Sensitivity And Selectivity ◽

Exo Iii ◽

Ag Ncs ◽

Recycling Amplification

A label-free DNA biosensor with high sensitivity and selectivity is constructed by using DNA–Ag NCs and Exo III-catalyzed target recycling amplification.

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Fluorescent Artificial Receptor-Based Membrane Assay (FARMA) for Spatiotemporally Resolved Monitoring of Biomembrane Permeability

10.26434/chemrxiv.9735152 ◽

2019 ◽

Author(s):

Frank Biedermann ◽

Garima Ghale, Ghale ◽

Andreas Hennig ◽

Werner M. Nau

Keyword(s):

High Throughput Screening ◽

High Sensitivity ◽

Point Of View ◽

Phospholipid Bilayer ◽

Label Free ◽

Microscopy Imaging ◽

Biophysical Models ◽

Fundamental Point ◽

Artificial Receptor ◽

Microplate Reader

The spatiotemporally resolved monitoring of membrane translocation, e.g., of drugs or toxins, has been a long-standing goal. Herein, we introduce the fluorescent artificial receptor-based membrane assay (FARMA), a facile, label-free method. With FARMA, the permeation of more than hundred organic compounds (drugs, toxins, pesticides, neurotransmitters, peptides, etc.) through vesicular phospholipid bilayer membranes has been monitored in real time (µs-h time scale) and with high sensitivity (nM-µM concentration), affording permeability coefficients across an exceptionally large range from 10–9‑10–3 cm s–1. From a fundamental point of view, FARMA constitutes a powerful tool to assess structure-permeability relationships and to test biophysical models for membrane passage. From an applied perspective, FARMA can be extended to high-throughput screening by adaption of the microplate reader format, to spatial monitoring of membrane permeation by microscopy imaging, and to the compartmentalized monitoring of enzymatic activity.

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