Patent ID: 8822184

Claim:
A novel preparation method of nanoparticle Janus assemblies comprising the steps of: (1) synthesizing gold nanoparticle (SU NPs) by reduction of HAuCl 4 using trisodium citrate; (2) preparing gold nanorods (Au NRs) by seed-mediated growth procedure; (3) coupling the synthesized Au NPs with first sulfydryl modified single strand oligonucleotides of SEQ ID NO: 1 (DNA1) to form gold nanoparticle-DNA1 conjugate (Au NP-DNA1); (4) coupling the prepared Au NRs with second sulfydryl modified single strand oligonucleotides of SEQ ID NO: 2 (DNA2) to an outer surface of Au NR to form DNA2 conjugate (Au NR-DNA2); (5) conjugating magnetic nanoparticles (MNP) with third amino modified single strand oligonucleotides of SEQ ID NO: 3 (DNA3) by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) procedure to form magnetic nanoparticles-DNA conjugates (MNP-DNA3), wherein the DNA2 is complementary to a first part of the DNA3; (6) hybridizing the prepared Au NR-DNA2 with MNP-DNA3 to form an assembly of the Au NR-DNA2 and MNP-DNA3; (7) after adding fourth single strand oligonucleotides of SEQ ID NO: 4 (DNA4) that is complementary to a second part of the DNA3 to hybridize DNA4 with DNA3 and form an assembly of Au NR-DNA2, DNA4 and MNP-DNA3, adding a DNA ligase to link the Au NR-DNA2 and the DNA4 in the assembly of Au NR-DNA2, DNA4 and MNP-DNA3; (8) dissociating the assembly of Au NR-DNA2, DNA4 and MNP-DNA3 formed in the step (7) at the melting temperature to free Au NR-DNA2-DNA4 from MNP-DNA3, then recovering the Au NR-DNA2-DNA4 through magnetic separation; (9) based on step (3) and (8), hybridizing the prepared Au NP-DNA1 with Au NR-DNA2-DNA4 to obtain binary plasmonic nanoparticles Janus assemblies; (10) characterizing the prepared binary nanoparticles Janus assemblies based on step (9) by transmission electron microscopy (TEM), circular dichroism spectra (CD) as well as synchotron small-angle X-ray scattering (S-SAXS).