title: Engineering plasmonic nanorod arrays for colon cancer marker detection.
abstract: Engineering plasmonic nanomaterials or nanostructures towards ultrasensitive biosensing for disease markers or pathogens is of high importance. Here we demonstrate a systematic approach to tailor effective plasmonic nanorod arrays by combining both comprehensive numerical discrete dipole approximations (DDA) simulation and transmission spectroscopy experiments. The results indicate that 200×50 nm nanorod arrays with 300×500 nm period provide the highest figure of merit (FOM) of 2.4 and a sensitivity of 310 nm/RIU. Furthermore, we demonstrate the use of nanorod arrays for the detection of single nucleotide polymorphism in codon 12 of the K-ras gene that are frequently occurring in early stages of colon cancer, with a sensitivity down to 10 nM in the presence of 100-fold higher concentration of the homozygous genotypes. Our work shows significant potential of nanorod arrays towards point-of-care applications in diagnosis and clinical studies.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Dodson
authors.affiliation: Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 5AG, United Kingdom.
authors.forename: Cuong
authors.initials: C
authors.lastname: Cao
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: Hamed
authors.initials: H
authors.lastname: Zaribafzadeh
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: Shuzhou
authors.initials: S
authors.lastname: Li
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore; NOVITAS, Nanoelectronics Centre of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore. Electronic address: qihua@ntu.edu.sg.
authors.forename: Qihua
authors.initials: Q
authors.lastname: Xiong
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000235:genetics*; D004252:DNA Mutational Analysis / Q000295:instrumentation; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005819:Genetic Markers / Q000235:genetics; D006801:Humans; D043942:Nanotubes / Q000737:chemistry / Q000648:ultrastructure; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D005819:Genetic Markers
keywords: Biosensing; Discrete dipole approximation; Localized surface plasmon resonance; Nanorod array; Plasmonics; Single nucleotide polymorphism