title: Spin-coated Au-nanohole arrays engineered by nanosphere lithography for a Staphylococcus aureus 16S rRNA electrochemical sensor.
abstract: The nanopatterning of gold nanoparticle (AuNP) arrays on an indium tin oxide (ITO) electrode using efficient and low-cost methods is described. This process used nanosphere lithography (NSL) encompassing the deposition of monolayered Polystyrene (PS) followed by a convective self-assembly drop coating protocol onto the ITO substrate that further acted as the mask after the AuNP assembly. The results showed that spin-coating allowed AuNPs to follow the contour and adhere to the PS nanospheres. The final products, after etching the PS, generated a highly ordered Au-nanohole array on an ITO substrate. The Au-nanohole arrays on the ITO electrode provided a greater surface area and successfully enhanced the peak current of electrochemical measurements by 82% compared with bare ITO and was used to detect Staphylococcus aureus 16S rRNA hybridization. In contrast to non-templated AuNP structures, the Au-nanohole arrays on the ITO electrode contributed to an optimum sensitivity improvement in DNA hybridization detection by 23%, along with an impressive limit of detection (LOD) of 10 pM. The high specificity of this distinguished structure was also achieved in the hybridization measurements of multi-analyte pathogens. These findings indicate that the combination of PS nanosphere lithography, followed by the spin-coating of AuNPs, leads to an inexpensive and simple engineering process that effectively generates uniform Au-nanohole arrays on ITO, which provides a greater surface area to optimize the electrochemical performance of the DNA biosensor.
authors.affiliation: Biomedical Engineering, Chang-Gung University, Taoyuan 333, Taiwan.
authors.forename: Agnes
authors.initials: A
authors.lastname: Purwidyantri
authors.affiliation: Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
authors.forename: Ching-Hsiang
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan; National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan.
authors.forename: Bing-Joe
authors.initials: BJ
authors.lastname: Hwang
authors.affiliation: Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan 333, Taiwan.
authors.forename: Ji-Dung
authors.initials: JD
authors.lastname: Luo
authors.affiliation: Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan 333, Taiwan.
authors.forename: Chiuan-Chian
authors.initials: CC
authors.lastname: Chiou
authors.affiliation: Kidney Research Center, Department of Nephrology, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan.
authors.forename: Ya-Chung
authors.initials: YC
authors.lastname: Tian
authors.affiliation: Kidney Research Center, Department of Nephrology, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan; Department of Medicine, Chang Gung University, Taoyuan 333, Taiwan.
authors.forename: Chan-Yu
authors.initials: CY
authors.lastname: Lin
authors.affiliation: Department of Medicine, Chang Gung University, Taoyuan 333, Taiwan; Department of Pediatrics, Division of Pediatric Nephrology, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan.
authors.forename: Chi-Hui
authors.initials: CH
authors.lastname: Cheng
authors.affiliation: Department of Electronic Engineering, Chang-Gung University, Taoyuan 333, Taiwan; Department of Materials Engineering, Ming-Chi University of Technology, New Taipei City 243, Taiwan. Electronic address: cslai@mail.cgu.edu.tw.
authors.forename: Chao-Sung
authors.initials: CS
authors.lastname: Lai
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D054802:Molecular Imprinting / Q000379:methods; D058608:Nanopores / Q000648:ultrastructure*; D012336:RNA, Ribosomal, 16S / Q000032:analysis / Q000235:genetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013211:Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification*
chemical_list: D012336:RNA, Ribosomal, 16S; D006046:Gold
keywords: 16S rRNA; Au-nanohole array; Electrochemical sensor; Nanosphere lithography (NSL); Spin-coated AuNPs; Staphylococcus aureus