Split aptamer-based detection of adenosine triphosphate using surface enhanced Raman spectroscopy and two kinds of gold nanoparticles.

An ultrasensitive and highly selective method is described for the determination of adenosine triphosphate (ATP) via surface-enhanced Raman scattering (SERS). Two split aptamers are used for specific recognition of ATP. They were attached to two SERS substrates. The first was placed on a nanolayer of gold nanoparticle-decorated graphene oxide (GO/Au3), and the other on gold nanoparticles (Au2). When ATP is introduced, it will interact with the split aptamers on the gold nanostructures to form a sandwich structure that brings the GO/Au3 nanolayer and the Au2 nanoparticle in close proximity. Consequently, the SERS signal, best measured at 1072 cm-1, is strongly enhanced. The sandwich structure also displays good water solubility and stability. Under optimized conditions, the SERS signal increases in the 10 pM - 10 nM ATP concentration range, and the limit of detection (LOD) is 0.85 pM. The method was applied to the determination of ATP in spiked human serum, and the LODs in serum and buffer are comparable. In our perception, the method has a wide scope in that numerous other aptamers may be used. This may result in a variety of other highly sensitive aptasensors for use in in-vitro diagnostics. Graphical abstract Schematic presentation of a self-assembly sandwich nanostructure as unique SERS assay platform for the sensitive detection of ATP.