title: A smartphone imaging-based label-free and dual-wavelength fluorescent biosensor with high sensitivity and accuracy.
abstract: The accuracy of a bioassay based on smartphone-integrated fluorescent biosensors has been limited due to the occurrence of false signals from non-specific reactions as well as a high background and low signal-to-noise ratios for complementary metal oxide semiconductor image sensors. To overcome this problem, we demonstrate dual-wavelength fluorescent detection of biomolecules with high accuracy. Fluorescent intensity can be quantified using dual wavelengths simultaneously, where one decreases and the other increases, as the target analytes bind to the split capture and detection aptamer probes. To do this, we performed smartphone imaging-based fluorescence microscopy using a microarray platform on a substrate with metal-enhanced fluorescence (MEF) using Ag film and Al2O3nano-spacer. The results showed that the sensitivity and specificity of the dual-wavelength fluorescent quantitative assay for the target biomolecule 17-β-estradiol in water were significantly increased through the elimination of false signals. The detection limit was 1pg/mL and the area under the receiver operating characteristic curve of the proposed assay (0.922) was comparable to that of an enzyme-linked immunosorbent assay (0.956) from statistical accuracy tests using spiked wastewater samples. This novel method has great potential as an accurate point-of-care testing technology based on mobile platforms for clinical diagnostics and environmental monitoring.
authors.affiliation: Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea.
authors.forename: Won-Il
authors.initials: WI
authors.lastname: Lee
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea.
authors.forename: Sajal
authors.initials: S
authors.lastname: Shrivastava
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea.
authors.forename: Le-Thai
authors.initials: LT
authors.lastname: Duy
authors.affiliation: SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea.
authors.forename: Bo
authors.initials: B
authors.lastname: Yeong Kim
authors.affiliation: Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea.
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Son
authors.affiliation: Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea; School of Advanced Materials Science and Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea; SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea. Electronic address: nelee@skku.edu.
authors.forename: Nae-Eung
authors.initials: NE
authors.lastname: Lee
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D004958:Estradiol / Q000737:chemistry / Q000302:isolation & purification*; D006801:Humans; D057230:Limit of Detection; D008856:Microscopy, Fluorescence; D053758:Nanoparticles / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D000068997:Smartphone / Q000295:instrumentation; D014867:Water / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D014867:Water; D012834:Silver; D004958:Estradiol; D000537:Aluminum Oxide
keywords: Dual-wavelength; Fluorescent biosensor; Metal enhanced fluorescence; Smartphone; Split aptamer