TEMPO-Cellulose Nanocrystal-Capped Gold Nanoparticles for Colorimetric Detection of Pathogenic DNA.
Keya GangulyDinesh K PatelSayan Deb DuttaKi-Taek LimPublished in: ACS omega (2021)
Nanocellulose-assisted gold nanoparticles are considered promising materials for developing eco-friendly diagnostic tools for biosensing applications. In this study, we synthesized 2,2,6,6-tetramethylpiperidin-1-piperidinyloxy (TEMPO)-oxidized cellulose nanocrystal (TEMPO-CNC)-capped gold nanoparticles (AuNPs) for the colorimetric detection of unamplified pathogenic DNA oligomers of methicillin-resistant Staphylococcus aureus. The fabricated TEMPO-CNC-AuNPs (TC-AuNPs) were characterized using UV-visible spectroscopy, transmission electron microscopy, atomic force microscopy, and dynamic light scattering. The average diameter of the synthesized AuNPs was approximately 30 nm. The aqueous solution of TC-AuNPs was stable and exhibited an absorption peak at 520 nm. The chemical interaction between TC-AuNPs and the surface charge of the target and non-target DNA determined the colorimetric differences under ionic conditions. A dramatic color change (red → blue) was observed in the TC-AuNP solution with the target DNA under ionic conditions due to the aggregation of AuNPs. However, no observable color change occurred in the TC-AuNP solution with the non-target DNA under similar conditions owing to the better shielding effects of the charged moieties. The colorimetric detection limit of the TC-AuNPs was demonstrated to be as low as 20 fM pathogenic DNA. Therefore, the use of TEMPO-oxidized CNC-capped AuNPs is efficient and straightforward as a biosensor for the colorimetric detection of pathogenic DNA.
Keyphrases
- gold nanoparticles
- circulating tumor
- single molecule
- aqueous solution
- cell free
- label free
- reduced graphene oxide
- atomic force microscopy
- methicillin resistant staphylococcus aureus
- sensitive detection
- loop mediated isothermal amplification
- ionic liquid
- circulating tumor cells
- real time pcr
- mass spectrometry
- solid state
- quantum dots
- optical coherence tomography