Bacteriophage M13 as a scaffold for preparing conductive polymeric composite fibers

Abstract

Using biological templates to build one-dimensional functional materials holds great promise in developing nanosized electrical devices, sensors, catalysts, and energy storage units. In this communication, we report a versatile assembly process for the preparation of water-soluble conductive polyaniline (PANi)/M13 composite nanowires by employing the bacteriophage M13 as a template. The surface lysine residues of M13 can be derivatized with carboxylic groups to improve its binding ability to the aniline; the resulting modifi ed M13 is denoted as m-M13. Highly negatively-charged poly(sulfonated styrene) was used both as a dopant acid and a stabilizing agent to enhance the stability of the composite fi bers in aqueous solution. A transparent solution of the conductive PANi/m-M13 composite fi bers can be readily obtained without any further purifi cation step. The fi bers can be easily fabricated into thin conductive fi lms due to their high aspect ratio and good solubility in aqueous solution. This synthesis discloses a unique and versatile way of using bionanorods to produce composite fi brillar materials with narrow dispersity, high aspect ratio, and high processibility, which may have many potential applications in electronics, optics, sensing, and biomedical engineering. KEYWORDSBacteriophage M13, nanofi ber, conductive polymer, self-assembly, bioconjugationThe controlled growth and fabrication of onedimensional (1-D) nanostructured objects such as fibers, tubes, and rods, is an emerging research area due to their potential applications in developing nanosized electric devices, sensors, catalysts, and energy storage units Previously we have shown that by using TMV as the template, 1-D polyaniline/TMV composite nanowires can be prepared by a head-to-tail selfassembly process of TMV [13,14] M13 is a cylindrical protein capsid consisting of 2700 identical major coat proteins as well as several minor coat proteins surrounding a single-stranded DNA genome. The rod-like M13 is 880 nm in length and 6.6 nm in diameter and one of the most studied rod-like viruses for developing new biocomposite materials [35]. Compared to the native TMV, a rod-like plant virus with a length of 300 nm and a diameter of 18 nm, the advantages of M13 are that it has a smaller diameter and higher aspect ratio, readily forms anisotropic thin fi lms and is much more pliable than TMV in solution. Thus, with M13 as a template, it should be possible to prepare more elastic composite fibers with smaller diameter, and better processability. Figure 1 shows a schematic illustration of the preparation of composite fi bers and a corresponding conductive thin fi lm of the PANi/M13 composite. We report here that conductive PANi/M13 composite nanowires can be readily obtained by incubation of M13 with poly(sulfonated styrene) (PSS) and ammonium persulfate (APS).Unmodified M13 was first used as the template to prepare PANi/M13 composite fi bers; however, we found that it was diffi cult to control the morphology of the final composite fibers due to...

Nanoscale bacteriophage biosensors beyond phage display

“…Such flexibility imparts multiple functions to the bacteriophage, and not surprisingly, has paved the way for the use of filamentous bacteriophage for a variety of multifunctional nanoprobes. [22][23][24][25][26][27][28][29] The most common form of filamentous bacteriophagebased biosensor is engineered by conjugating targeting moieties and fluorescent molecules onto the capsid surface, ultimately for the detection of target analyte and for the transduction of signal via fluorescence. 30,31 For example, Li et al 9 constructed a bacteriophage capable of targeting a HeLa contaminant KB cell line and emitting fluorescence upon target binding ( Figure 4A) Another common type of genetically-engineered filamentous bacteriophage-based sensor involves the conjugation of nanoparticles to the capsid, in which the unique properties of each type of nanoparticle is exploited in an application-specific manner.…”

Direct detection and measurement of wall shear stress using a filamentous bio-nanoparticle

“…Reported here is a strategy for measuring WSS by using labeled M13 bacteriophage (M13) as a microfluidic reporter. Previous work has reported its use as a scaffold for nanowires [13][14][15] and fibres [16,17], as a biosensor [18], in drug delivery [19], as a cancer marker [20], and in the detection of biological molecules [18]. M13 is a long (~900 nm) and thin (~7 nm) semi-rigid construct whose persistence length is ~1,400 nm [21].…”

M13 bacteriophage-polymer nanoassemblies as drug delivery vehicles

“…M13 can be inexpensively purified in large quantity and has been employed extensively in many applications ranging from functional materials to novel biomedical applications [19,35,36]. The structure of the M13 bacteriophage is well-defined and can be genetically engineered to produce conductive fibers [35] or display peptides or proteins in controlled orientations [31,36,37].…”

“…M13 can be inexpensively purified in large quantity and has been employed extensively in many applications ranging from functional materials to novel biomedical applications [19,35,36]. The structure of the M13 bacteriophage is well-defined and can be genetically engineered to produce conductive fibers [35] or display peptides or proteins in controlled orientations [31,36,37]. Additionally, a variety of functionalities, including drugs [19,[38][39][40][41], arginine-glycine-aspartic (RGD) peptides [36], and fluorescent dyes [42,43], can be chemically anchored on the surface of M13 bacteriophage.…”