Resonance scattering spectral detection of trace ATP based on label-free aptamer reaction and nanogold catalysis

Abstract

Double-stranded DNA (dsDNA) cannot protect gold nanoparticles (AuNPs) in the presence of NaCl, and dsDNA interacted with adenosine triphosphate (ATP) to form stable G-quartet and a single-stranded DNA (DNA 2) that can protect AuNPs. The unprotected AuNPs were aggregated to AuNP aggregations (AuNPA) that exhibited a resonance scattering (RS) peak at 590 nm. The RS intensity at 590 nm decreased linearly when the ATP concentration increased in the range of 6.6–110 nM. The catalysis of AuNP–DNA 2 was stronger than that of the AuNPA on the glucose–Cu(II) particle reaction, and the product appeared as an RS peak at 620 nm. When the ATP concentration was increased, the AuNP–DNA 2 increased, and the RS intensity at 620 nm increased linearly. The increased RS intensity (ΔI_620 nm) was linear to ATP concentration in the range of 2.2–220 nM, with a regression equation of ΔI_620 nm = 0.709C + 7.7, and a detection limit of 0.5 nM. Hereby, a new RS method of ATP detection was set up with high sensitivity and selectivity.