The aggregation of gold nanoparticles (AuNPs) is known to induce an enhancement of localized surface plasmon resonance due to the coupling of plasmonic fields of adjacent nanoparticles. Here we show that AuNPs aggregation also causes a significant enhancement of chemiluminescence in the presence of luminophores. The phenomenon is used to introduce a rapid and sensitive DNA detection method that does not require amplification. DNA probes conjugated to AuNPs were used to detect a DNA target sequence specific to the fungus Ceratocystis fagacearum, causal agent of oak wilt. The hybridization of the DNA target with the DNA probes results in instantaneous aggregation of AuNPs into nanoballs, leading to a significant enhancement of luminol chemiluminescence. The enhancement reveals a linear correlation (R2 = 0.98) to the target DNA concentration, with a limit of detection down to 260 fM (260 × 10-15 M), two orders of magnitude higher than the performance obtained with plasmonic colorimetry and absorption spectrometry of single gold nanoparticles. Furthermore, the detection can be performed within 22 min using only a portable luminometer.
Bibliographical noteFunding Information:
This work is mainly supported by he Minnesota Environment and Natural Resource Trust Fund as recommended by the Legislative Citizen Commission on Minnesota’s Resources, through the Minnesota Invasive Terrestrial Plants and Pests Center, and contributions from the National Science Foundation project award No 1605191, the University of Minnesota MnDRIVE Global Food Venture, and USDA National Institute of Food and Agriculture, Hatch project 1006789.
© 2017 The Author(s).