title: Effects of nanoparticle size and cell type on high sensitivity cell detection using a localized surface plasmon resonance biosensor.
abstract: A localized surface plasmon resonance (LSPR) effect was used to distinguish cell concentration on ordered arrays of Au nanoparticles (NPs) on glass substrates. Human-derived retinal pigment epithelial RPE-1 cells with flatter bodies and higher confluency were compared with breast cancer MCF-7 cells. Nanosphere lithography was used to form Au NPs with average diameters of 500 and 60 nm in order to compare cell detection range, resonance peak shift, and cell concentration sensitivity. A larger cell concentration range was detected on the larger 500 nm Au NPs compared to 60 nm Au NPs (8.56 × 10(3)-1.09 × 10(6) vs. 3.43 × 10(4)-2.73 × 10(5)cells/ml). Resonance peak shift could distinguish RPE-1 from MCF-7 cells on both Au NPs. RPE-1 cells consistently displayed larger resonance peak shifts compared to MCF-7 cells until the detection became saturated at higher concentration. For both types of cells, higher concentration sensitivity in the range of ~10(4)-10(6)cells/ml was observed on 500 nm compared to 60 nm Au NPs. Our results show that cells on Au NPs can be detected in a large range and at low concentration. Optimal cell sensing can be achieved by altering the dimensions of Au NPs according to different cell characteristics and concentrations.
authors.affiliation: Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong; Center for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong; Department of Electronic Information Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong; Center for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Matthew Man-Kin
authors.initials: MM
authors.lastname: Wong
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong; Center for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Sung-Kay
authors.initials: SK
authors.lastname: Chiu
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong; Center for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Hao
authors.initials: H
authors.lastname: Lin
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong; Center for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Johnny C
authors.initials: JC
authors.lastname: Ho
authors.affiliation: Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong; Center for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong. Electronic address: pang@cityu.edu.hk.
authors.forename: Stella W
authors.initials: SW
authors.lastname: Pang
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002452:Cell Count / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D006046:Gold
keywords: Au nanoparticles; Breast cancer MCF-7 cell; Cell concentration detection; Human-derived retinal pigment epithelial RPE-1 cell; Localized surface plasmon resonance (LSPR); Resonance peak shift