Detection of Adenosine Triphosphate with an Aptamer Biosensor Based on Surface-Enhanced Raman Scattering

Abstract

A simple, ultrasensitive, highly selective, and reagent-free aptamer-based biosensor has been developed for quantitative detection of adenosine triphosphate (ATP) using surface-enhanced Raman scattering (SERS). The sensor contains a SERS probe made of gold nanostar@Raman label@SiO(2) core-shell nanoparticles in which the Raman label (malachite green isothiocyanate, MGITC) molecules are sandwiched between a gold nanostar core and a thin silica shell. Such a SERS probe brings enhanced signal and low background fluorescence, shows good water-solubility and stability, and exhibits no sign of photobleaching. The aptamer labeled with the SERS probe is designed to hybridize with the cDNA on a gold film to form a rigid duplex DNA. In the presence of ATP, the interaction between ATP and the aptamer results in the dissociation of the duplex DNA structure and thereby removal of the SERS probe from the gold film, reducing the Raman signal. The response of the SERS biosensor varies linearly with the logarithmic ATP concentration up to 2.0 nM with a limit of detection of 12.4 pM. Our work has provided an effective method for detection of small molecules with SERS.

Aptamer-based Colorimetric and Chemiluminescence Detection of Aflatoxin B1 in Foods Samples

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DNA Nanobiosensors: An Outlook on Signal Readout Strategies

“…(g) SERS-based readout: an ATP-binding aptamer is bound to a single-stranded probe on a gold surface. The presence of ATP triggers conformational change of the aptamer causing it to dissociate from the probe, resulting in a loss of the SERS signal [29].…”

“…In typical SERS assays, Raman reporters are attached to the surface of metallic nanoparticles (the SERS substrates) and covered by a protective shell (Figure 2(g), top) that prevents leaching out of the Raman reporters and improves water solubility and stability [54,55]. In one such example, an aptamer-based biosensor was designed to detect ATP using SERS [29]. This study used malachite green isothiocyanate as the Raman reporter which was sandwiched between a gold nanostar core and a silica shell.…”

Polarization dependence of transverse photo-induced voltage in gold thin film with random nanoholes

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