Construction Of New Gold Nano Probes And Applications In Nucleic Acid Detection And Logic Gates

Due to the good biocompatibility, gold nanoparticles have been widely used in bioanalytical chemistry. This paper discusses of the fabircation of gold nanoprobes,which were used in nucleic acid and protein detection. The established methods exhibited high selectivity and sensitivity, simple operation, etc., which have broad application prospects in the development of new biosensors, disease research and clinical biomedicine.1. Linear light-scattering of gold nanostars for versatile biosensing of nucleic acids and proteins using exonuclease III as biocatalyst to signal amplificationWe demonstrate a facile method for room-temperature synthesis of gold nanostars(Au NSs) with a size of ~50 nm via seeded growth. Significantly, the Au NSs are found to have high light-scattering properties, which are successfully used as labels for sensitive and selective detection of nucleic acids and proteins by using exonuclease III(Exo III) as a biocatalyst. Moreover, a binding-induced DNA three-way junction(DNA TWJ) is introduced to thrombin detection, in which the binding of two aptamers to thrombin triggers assembly of the DNA motifs and initiates the subsequent DNA strand displacement reaction(SDR) and Exo III-assisted cascade recycling amplification. The detection limits of 89 f M and 5.6p M are achieved for DNA and thrombin, respectively. It is noteworthy that based on the DNA TWJ strategy the sequences are independent on target proteins.Additionally, the employment of MNPs in the assays can not only simplify the operations but also reduce background noise, leading to an improvement of detection sensitivity.2. Detection of nucleic acid using magnetic graphene oxide-gold nanoparticle probes and its application in logic gate.Magnetic oxide graphene has the advantage of rapid separation and convenient operation, while gold nanoparticles can be easily applied to colorimetric analysis. In this experiment, we explored the two comprehensive advantages of the magnetic graphene oxide and gold nanoparticles, which was used for the detection of nucleic acid. The proposed method was simple and the results can be easily observed.Moreover, this method was applied to logic gate operation, achieving diverse detection of nucleic acids.