title: Instrument-Free Synthesizable Fabrication of Label-Free Optical Biosensing Paper Strips for the Early Detection of Infectious Keratoconjunctivitides.
abstract: We introduce a surface-enhanced Raman scattering (SERS)-functionalized, gold nanoparticle (GNP)-deposited paper strip capable of label-free biofluid sensing for the early detection of infectious eye diseases. The GNP biosensing paper strip was fabricated by the direct synthesis and deposition of GNPs on wax-divided hydrophilic areas of a permeable porous substrate through a facile, power-free synthesizable, and highly reproducible successive ionic layer absorption and reaction (SILAR) technique. To maximize localized surface plasmon resonance-generated SERS activity, the concentration of the reactive solution and number of SILAR cycles were optimized by controlling the size and gap distance of GNPs and verified by computational modeling with geometrical hypotheses of Gaussian-estimated metallic nanoparticles. The responses of our SERS-functionalized GNP paper strip to Raman intensities exhibited an enhancement factor of 7.8 × 10(8), high reproducibility (relative standard deviation of 7.5%), and 1 pM 2-naphthalenethiol highly sensitive detection limit with a correlation coefficient of 0.99, achieved by optimized SILAR conditions including a 10/10 mM/mM HAuCl4/NaBH4 concentration and six SILAR cycles. The SERS-functionalized GNP paper is supported by a multivariate statistics-preprocessed machine learning-judged bioclassification system to provide excellent label-free chemical structure sensitivity for identifying infectious keratoconjunctivitis. The power-free synthesizable fabrication, label-free, rapid analysis, and high sensitivity feature of the SILAR-fabricated SERS-functionalized GNP biosensing paper strip makes it an excellent alternative in point-of-care applications for the early detection of various infectious diseases.
authors.affiliation: Department of Medical Engineering, Graduate School, Kyung Hee University , Seoul 02447, Korea.
authors.forename: Wansun
authors.initials: W
authors.lastname: Kim
authors.affiliation: Department of Biomedical Engineering, College of Medicine, Kyung Hee University , Seoul 02447, Korea.
authors.forename: Jae-Chul
authors.initials: JC
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, College of Medicine, Kyung Hee University , Seoul 02447, Korea.
authors.forename: Jae-Ho
authors.initials: JH
authors.lastname: Shin
authors.affiliation: Department of Ophthalmology, College of Medicine, Kyung Hee University , Seoul 02447, Korea.
authors.forename: Kyung-Hyun
authors.initials: KH
authors.lastname: Jin
authors.affiliation: Department of Medical Engineering, Graduate School, Kyung Hee University , Seoul 02447, Korea.|Department of Biomedical Engineering, College of Medicine, Kyung Hee University , Seoul 02447, Korea.
authors.forename: Hun-Kuk
authors.initials: HK
authors.lastname: Park
authors.affiliation: Department of Medical Engineering, Graduate School, Kyung Hee University , Seoul 02447, Korea.|Department of Biomedical Engineering, College of Medicine, Kyung Hee University , Seoul 02447, Korea.
authors.forename: Samjin
authors.initials: S
authors.lastname: Choi
mesh_terms: D015374:Biosensing Techniques; D006046:Gold / Q000737:chemistry; D006801:Humans; D007637:Keratoconjunctivitis / Q000175:diagnosis*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry; D009281:Naphthalenes / Q000032:analysis*; D010209:Paper; D019095:Point-of-Care Systems; D016062:Porosity; D025341:Principal Component Analysis; D013059:Spectrum Analysis, Raman; D013438:Sulfhydryl Compounds / Q000032:analysis*; D013666:Tears / Q000737:chemistry*
chemical_list: D009281:Naphthalenes; D013438:Sulfhydryl Compounds; D006046:Gold; C401958:2-naphthalenethiol