title: Exploring the flexible chemistry of 4-fluoro-3-nitrophenyl azide for biomolecule immobilization and bioconjugation.
abstract: Bioconjugation and functionalization of polymer surfaces are two major tasks in materials chemistry which are accomplished using a variety of coupling agents. Immobilization of biomolecules onto polymer surfaces and the construction of bioconjugates are essential requirements of many biochemical assays and chemical syntheses. Different linkers with a variety of functional groups are used for these purposes. Among them, the benzophenones, aryldiazirines, and arylazides represent the most commonly used photolinker to produce the desired chemical linkage upon their photo-irradiation. In this review, we describe the versatile applications of 4-fluoro-3-nitrophenyl azide, one of the oldest photolinkers used for photoaffinity labeling in the late 1960s. Surprisingly, this photolinker, historically known as 1-fluoro-2-nitro-4-azidobenzene (FNAB), has remained unexplored for a long time because of apprehension that FNAB forms ring-expanded dehydroazepine as a major product and hence cannot activate an inert polymer. The first evidence of photochemical activation of an inert surface by FNAB through nitrene insertion reaction was reported in 2001, and the FNAB-activated surface was found to conjugate a biomolecule without any catalyst, reagent, or modification. FNAB has distinct advantages over perfluorophenyl azide derivatives, which are contemporary nitrene-generating photolinkers, because of its simple, single-step preparation and ease of thermochemical and photochemical reactions with versatile polymers and biomolecules. Covering these aspects, the present review highlights the flexible chemistry of FNAB and its applications in the field of surface engineering, immobilization of biomolecules such as antibodies, enzymes, cells, carbohydrates, oligonucleotides, and DNA aptamers, and rapid diagnostics. Graphical Abstract An overview of the FNAB-engineered activated polymer surfaces for covalent ligation of versatile biomolecules.
authors.affiliation: CSIR - Institute of Genomics and Integrative Biology, Mall Road, 110007, Delhi, India.|Department of Biotechnology, Delhi Technological University, Main Bawana Road, 110042, Delhi, India.
authors.forename: Saroj
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado, Denver, Colorado, 80045, USA.
authors.forename: Dileep
authors.initials: D
authors.lastname: Kumar
authors.affiliation: CSIR - Institute of Genomics and Integrative Biology, Mall Road, 110007, Delhi, India.|Academy of Scientific and Innovative Research, Mathura Road, Jasola, 110020, New Delhi, India.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Ahirwar
authors.affiliation: CSIR - Institute of Genomics and Integrative Biology, Mall Road, 110007, Delhi, India. pnahar@igib.res.in.|Academy of Scientific and Innovative Research, Mathura Road, Jasola, 110020, New Delhi, India. pnahar@igib.res.in.|Dr. Nahar's New Idea lab, C-202, Ramkrishan Cooperative Group Housing Society, Plot 12, Sector 23, Dwarka, New Delhi, India. pnahar@igib.res.in.
authors.forename: Pradip
authors.initials: P
authors.lastname: Nahar
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry; D001386:Azides / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D002241:Carbohydrates / Q000737:chemistry; D018914:Cells, Immobilized / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry*; D055616:Microtechnology / Q000379:methods; D019920:Photoaffinity Labels / Q000737:chemistry; D055668:Photochemical Processes
chemical_list: D052157:Aptamers, Nucleotide; D001386:Azides; D002241:Carbohydrates; D055767:Immobilized Proteins; D019920:Photoaffinity Labels; C007753:4-fluoro-3-nitrophenyl azide
keywords: 1-Fluoro-2-nitro-4-azidobenzene; Biomolecules; Immobilization; Inert surface; Photolinker; Polymer