title: T7 bacteriophage induced changes of gold nanoparticle morphology: biopolymer capped gold nanoparticles as versatile probes for sensitive plasmonic biosensors.
abstract: The morphological changes of gold nanoparticles induced by T7 virus (bacteriophage) and the determination of its femtomolar concentration by a plasmonic method are presented. Carboxymethyl chitosan capped gold nanoparticles (CMC-AuNPs) are used as plasmonic probes and are synthesized by a simple one pot wet chemical method. HR-TEM images show that the spherical structure of the CMC-AuNPs is changed into chain-like nanostructures after the addition of T7 virus due to the strong coordination of CMC-AuNPs with T7. Since T7 capsids comprise a repeating motif of capsomers built from proteins that bind to the acid groups of chitosan, the conjugation of carboxymethyl chitosan-linked AuNPs with T7 virions enables colorimetric biosensing detection. The absorbance intensity (∼610 nm) increases in the concentration range of T7 from 2 × 10(-15) M to 2 × 10(-13) M and the detection limit is found to be 2 × 10(-15) M (2 fM). The present work demonstrates eco-friendly biopolymer stabilized AuNPs as potential nanomaterials for biosensing of viruses. Our method is very simple, low cost, selective and highly sensitive, and provides new insight into virus induced chain-like morphology of AuNPs.
authors.affiliation: Institute of Physical Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland. joaniek@ichf.edu.pl.
authors.forename: Palanisamy
authors.initials: P
authors.lastname: Kannan
authors.forename: Marcin
authors.initials: M
authors.lastname: Los
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Los
authors.forename: Joanna
authors.initials: J
authors.lastname: Niedziolka-Jonsson
mesh_terms: D017123:Bacteriophage T7 / Q000302:isolation & purification*; D048271:Chitosan / Q000031:analogs & derivatives / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: C514968:carboxymethyl-chitosan; D006046:Gold; D048271:Chitosan