Rapid and PCR-free DNA Detection by Nanoaggregation-Enhanced Chemiluminescence

Abdennour Abbas,Olga Saiapina,Alexandra Feltmeyer,Renu Singh,Jennifer Juzwik,Brett Arenz

doi:10.1038/s41598-017-14580-w

Abdennour Abbas, Olga Saiapina + Show 4 more

Open Access

https://doi.org/10.1038/s41598-017-14580-w

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Abstract

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.

Highlights

Gold nanoparticles (AuNPs) are widely used nanomaterials for their excellent electric, catalytic, and optical properties[1]
Nanoparticle aggregation is caused by the hybridization of the target DNA with DNA probes attached to gold nanoparticles
The method was demonstrated by the specific detection of C. fagacearum, the causal agent of wilt in oak trees, and confirmed by isolation on agar and by polymerase chain reaction (PCR)

Summary

Results and Discussion

To demonstrate the concept of nanoparticle aggregation-enhanced chemiluminescence, the fungus Ceratocystis fagacearum was used as a model pathogen. Nucleotides should have the proper lengths to provide the specific detection of the target: hybridization of two DNA probes with target strand should eliminate possible interferences with non-targets Based on these characteristics, we hypothesized that the assembly or aggregation of gold nanoparticles would affect the catalytic activity of the plasmonic nanoparticles and would induce a change in chemiluminescence intensity. The samples analyzed by chemiluminescence detection were subjected to the analysis by nested polymerase chain reaction (PCR) technique to confirm the presence or absence of the target DNA associated with C. fagacearum.

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