Label-free, zeptomole cancer biomarker detection by surface-enhanced fluorescence on nanoporous gold disk plasmonic nanoparticles.
We experimentally demonstrate a label-free biosensor for the ERBB2 cancer gene DNA target based on the distance-dependent detection of surface-enhanced fluorescence (SEF) on nanoporous gold disk (NPGD) plasmonic nanoparticles. We achieve detection of 2.4 zeptomole of DNA target on the NPGD substrate with an upper concentration detection limit of 1 nM. Without the use of molecular spacers, the NPGD substrate as an SEF platform was shown to provide higher net fluorescence for visible and NIR fluorophores compared to glass and non-porous gold substrates. The enhanced fluorescence signals in patterned nanoporous gold nanoparticles make NPGD a viable material for further reducing detection limits for biomolecular targets used in clinical assays. With patterned nanoporous gold disk (NPGD) plasmonic nanoparticles, a label-free biosensor that makes use of distance-dependent detection of surface-enhanced fluorescence (SEF) is constructed and tested for zeptomole detection of ERBB2 cancer gene DNA targets.
Department of Electrical and Computer Engineering, University of Houston, 4800 Calhoun Road, Houston, Texas, 77204, USA.
Greggy M
GM
Santos
Department of Electrical and Computer Engineering, University of Houston, 4800 Calhoun Road, Houston, Texas, 77204, USA.
Fusheng
F
Zhao
Department of Electrical and Computer Engineering, University of Houston, 4800 Calhoun Road, Houston, Texas, 77204, USA.
Jianbo
J
Zeng
Department of Electrical and Computer Engineering, University of Houston, 4800 Calhoun Road, Houston, Texas, 77204, USA.
Ming
M
Li
Department of Electrical and Computer Engineering, University of Houston, 4800 Calhoun Road, Houston, Texas, 77204, USA. wshih@uh.edu.
Wei-Chuan
WC
Shih
D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D002232:Carbocyanines / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D009693:Nucleic Acid Hybridization; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013455:Sulfur / Q000737:chemistry; D013499:Surface Properties
D014408:Biomarkers, Tumor; D002232:Carbocyanines; D004277:DNA, Single-Stranded; C089187:cyanine dye 3; D013455:Sulfur; D006046:Gold
label-free biosensor; molecular beacon; nanoporous gold disks; surface-enhanced fluorescence; zeptomole detection