Nanospheres by citrate reduction of aucl3 for their usage in dna hybridization biosensors

Aim. In this work, we describe a reliable and straightforward method of synthesis of monodisperse spherical gold nanoparticles (AuNPs) for DNA labeling in hybridization biosensors based on surface plasmon resonance (SPR) spectrometry. Materials and Methods. Several samples of colloid AuNPs were prepared by citrate reduction of gold (III) chloride and studied with dynamic light scattering to determine their distribution by diameter. The samples with the least variance of AuNP diameters (8–33 nm) were designated for labeling of DNA probes used to amplify the signal of the SPR-based hybridization DNA biosensor. Results. The experiments showed the possibility of the synthesis of precision AuNPs from gold (III) chloride through control of the duration of their boiling. An optimal variation of the method of synthesis of such AuNPs was proposed. AuNPs synthesized by the described method were instrumental in achieving a substantial specific increase in biosensor signal. Conclusions. The proposed method can be used to produce precision citrate-capped AuNPs suitable for use in a wide range of biosensors.