Covalent Immobilization of Peptides onto Reactive Latexes

Gas-phase etching and optical lithography were employed for the fabrication of a silicon nanoribbon chip (Si-NR chip). The quality of the so-fabricated silicon nanoribbons (Si-NRs) was monitored by optical Raman scattering spectroscopy. It was demonstrated that the structures of the Si-NRs were virtually defect-free, meaning they could be used for highly sensitive detection of biological macromolecules. The Si-NR chips were then used for the highly sensitive nanoelectronics detection of DNA oligonucleotides (oDNAs), which represent synthetic analogs of 106a-5p microRNA (miR-106a-5p), associated with the development of autism spectrum disorders in children. The specificity of the analysis was attained by the sensitization of the Si-NR chip sur-face by covalent immobilization of oDNA probes, whose nucleotide sequence was complementary to the known sequence of miR-106a-5p. The use of the Si-NR chip was demonstrated to al-low for the rapid label-free real-time detection of oDNA at ultra-low (~10−17 M) concentrations.

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A simple method to construct a low-cost immunosensor based on a dithiol-functionalized polydopamine platform

New Journal of Chemistry ◽

10.1039/d0nj06241c ◽

2021 ◽

Author(s):

Bo Liu ◽

Luanying Yang ◽

Gang Wang ◽

Sha He ◽

Xiaobo Wang ◽

...

Keyword(s):

Detection Limit ◽

Linear Response ◽

Low Cost ◽

Covalent Immobilization ◽

The Self ◽

Simple Method ◽

Low Detection Limit

A simple and low-cost electrochemical CEA immunosensor was investigated via the self-polymerization of dopamine and a dithiol compound spacer for the covalent immobilization of antibodies. The designed CEA immunosensor exhibited a linear response and a low detection limit.

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Green Production of Cladribine by Using Immobilized 2′-Deoxyribosyltransferase from Lactobacillus delbrueckii Stabilized through a Double Covalent/Entrapment Technology

Biomolecules ◽

10.3390/biom11050657 ◽

2021 ◽

Vol 11 (5) ◽

pp. 657

Author(s):

Cintia Wanda Rivero ◽

Natalia Soledad García ◽

Jesús Fernández-Lucas ◽

Lorena Betancor ◽

Gustavo Pablo Romanelli ◽

...

Keyword(s):

Silica Nanoparticles ◽

Enzymatic Synthesis ◽

Calcium Alginate ◽

Covalent Immobilization ◽

Chemical Processes ◽

Lactobacillus Delbrueckii ◽

Proof Of Concept ◽

Enzymatic Production ◽

Green Production ◽

Efficient Alternative

Nowadays, enzyme-mediated processes offer an eco-friendly and efficient alternative to the traditional multistep and environmentally harmful chemical processes. Herein we report the enzymatic synthesis of cladribine by a novel 2′-deoxyribosyltransferase (NDT)-based combined biocatalyst. To this end, Lactobacillus delbrueckii NDT (LdNDT) was successfully immobilized through a two-step immobilization methodology, including a covalent immobilization onto glutaraldehyde-activated biomimetic silica nanoparticles followed by biocatalyst entrapment in calcium alginate. The resulting immobilized derivative, SiGPEI 25000-LdNDT-Alg, displayed 98% retained activity and was shown to be active and stable in a broad range of pH (5–9) and temperature (30–60 °C), but also displayed an extremely high reusability (up to 2100 reuses without negligible loss of activity) in the enzymatic production of cladribine. Finally, as a proof of concept, SiGPEI 25000-LdNDT-Alg was successfully employed in the green production of cladribine at mg scale.

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