Liquid crystal droplets functionalized with charged surfactant and polyelectrolyte for non-specific protein detection

RSC Advances ◽  
2015 ◽  
Vol 5 (118) ◽  
pp. 97264-97271 ◽  
Author(s):  
Lei Yang ◽  
Mashooq Khan ◽  
Soo-Young Park
Keyword(s):  
Liquid Crystal ◽  
Protein Detection ◽  
Specific Protein

5CBsurfactant droplets were coated with polyelectrolytes for utilization of non-specific protein detection.

scholarly journals Sensitive protein detection using site-specifically oligonucleotide-conjugated nanobodies

2022 ◽  
Author(s):  
Rasel A. Al-Amin ◽  
Phathutshedzo M. Muthelo ◽  
Eldar Abdurakhmanov ◽  
Cecile Vincke ◽  
Serge Muyldermans ◽  
...  
Keyword(s):  
Polyclonal Antibodies ◽  
Protein Detection ◽  
Specific Protein ◽  
Protein Biomarkers ◽  
High Quality ◽  
Affinity Reagents ◽  
Protein Assay ◽  
Enzyme Coupling ◽  
Target Binding ◽  
Dna Strand

High-quality affinity probes are critical for sensitive and specific protein detection, in particular to detect protein biomarkers at early phases of disease development. Clonal affinity reagents can offer advantages over the commonly used polyclonal antibodies (pAbs) in terms of reproducibility and standardization of such assays. In particular, clonal reagents offer opportunities for site-directed attachment of exactly one modification per affinity reagent at a site designed not to interfere with target binding to help standardize assays. The proximity extension assays (PEA) is a widely used protein assay where pairs of protein-binding reagents are modified with oligonucleotides (oligos), so that their proximal binding to a target protein generates a reporter DNA strand for DNA-assisted readout. The assays have been used for high-throughput multiplexed protein detection of up to a few thousand different proteins in one or a few microliters of plasma. Here we explore nanobodies (Nb) as an alternative to polyclonal antibodies pAbs as affinity reagents for PEA. We describe an efficient site-specific approach for preparing high-quality oligo-conjugated Nb probes via Sortase A (SrtA) enzyme coupling. The procedure allows convenient removal of unconjugated affinity reagents after conjugation. The purified high-grade Nb probes were used in PEA and the reactions provided an efficient means to select optimal pairs of binding reagents from a group of affinity reagents. We demonstrate that Nb-based PEA for interleukin-6 (IL6) detection can augment assay performance, compared to the use of pAb probes. We identify and validate Nb combinations capable of binding in pairs without competition for IL6 antigen detection by PEA.

scholarly journals Aptamer-Based Biosensing with a Cationic AIEgen

2019 ◽  
Vol 72 (8) ◽  
pp. 620 ◽  
Author(s):  
Tracey Luu ◽  
Mengjie Liu ◽  
Yilong Chen ◽  
Roozbeh Hushiarian ◽  
Anthony Cass ◽  
...  
Keyword(s):  
High Selectivity ◽  
Low Cost ◽  
Protein Detection ◽  
Specific Protein ◽  
Personal Health ◽  
Fluorescence Signal ◽  
Portable Devices ◽  
Dye Molecules ◽  
Working Mechanism ◽  
Aptamer Sequence

Fabrication of low-cost biosensing platforms with high selectivity and sensitivity is important for constructing portable devices for personal health monitoring. Herein, we report a simple biosensing strategy based on the combination of a cationic AIEgen (aggregation-induced emission fluorogen), TPE-2+, with an aptamer for specific protein detection. The target protein can displace the dye molecules on the dye–aptamer complex, resulting in changes in the fluorescence signal. Selectivity towards different targets can be achieved by simply changing the aptamer sequence. The working mechanism is also investigated.

Nano-functionalized long-period fiber grating probe for disease-specific protein detection

2018 ◽  
Vol 6 (3) ◽  
pp. 386-392 ◽  
Author(s):  
Deependra Tyagi ◽  
Satyendra Kumar Mishra ◽  
Bing Zou ◽  
Congcong Lin ◽  
Ting Hao ◽  
...  
Keyword(s):  
Real Time ◽  
Protein Detection ◽  
Specific Protein ◽  
Fiber Grating ◽  
Label Free ◽  
Long Period Fiber Grating ◽  
Long Period ◽  
Specific Proteins ◽  
Period Fiber Grating ◽  
Disease Specific

Label-free nano-functionalized LPFG based real-time, reusable sensor for sensitive detection of disease-specific proteins.

Research highlights: nanopore protein detection and analysis

Lab on a Chip ◽  
2015 ◽  
Vol 15 (17) ◽  
pp. 3424-3427 ◽  
Author(s):  
Shiv Acharya ◽  
Shayson Edwards ◽  
Jacob Schmidt
Keyword(s):  
Protein Folding ◽  
Protein Concentration ◽  
Protein Detection ◽  
Specific Protein ◽  
Protein Species ◽  
Concentration Determination

Nanopore detection of specific protein species using carrier DNA – Quantitative protein concentration determination using aptamers – Protein folding studied with unfoldase-coupled nanopores.

scholarly journals An Activity-Based Methionine Bioconjugation Approach to Developing Proximity-Activated Imaging Reporters

2019 ◽  
Author(s):  
Jun Ohata ◽  
Lakshmi Krishnamoorthy ◽  
Monica Gonzalez ◽  
Tong Xiao ◽  
Diana Iovan ◽  
...  
Keyword(s):  
Protein Detection ◽  
Specific Protein ◽  
Protein Activity ◽  
Protein Targets ◽  
Sensing Platform ◽  
Starting Point ◽  
Methionine Residues ◽  
Endogenous Activity

Chemical probes that report on protein activity, rather than protein abundance, with spatial and temporal resolution can enable studies of their native function in biological contexts as well as provide opportunities for developing new types of biochemical reporters. Here we present a sensing platform, termed proximity-activated imaging reporter (PAIR), which combines activity-based methionine bioconjugation and antibody labeling with proximity-dependent oligonucleotide-based amplification to monitor dynamic changes of a given analyte in cells and animals through context-dependent methionine labeling of specific protein targets. We establish this PAIR method to develop sensors for imaging reactive oxygen species (ROS) and calcium ions through oxaziridine-directed labeling of reactive methionine residues on β-actin and calmodulin (CaM), respectively, where the extent of methionine bioconjugation on these protein targets can serve as an indicator of oxidative stress or calcium status. In particular, application of PAIR to activity-based CaM detection provides a method for imaging integrated calcium activity in both in vitro cell and in vivo zebrafish models. By relying on native protein biochemistry, PAIR enables redox and metal imaging without introduction of external small-molecules or genetically encoded indicators that can potentially buffer the natural/existing pools. This approach can be potentially generalized to target a broader range of analytes by pairing appropriate activity-based protein probes with protein detection reagents in a proximity-driven manner, providing a starting point not only for designing new sensors but also for monitoring endogenous activity of specific protein targets in biological specimens with spatial and temporal fidelity.

Sign in / Sign up

Export Citation Format

Share Document