title: Improved molecular fingerprint analysis employing multi-branched gold nanoparticles in conjunction with surface-enhanced Raman scattering.
abstract: Vibrational spectroscopy is a powerful analytical tool that assesses molecular properties based on spectroscopic signatures. In this study, the effect of gold nanoparticle morphology (spherical vs multi-branched) was assessed for the characterization of a Raman signal (ie, molecular fingerprint) that may be helpful for numerous medical applications. Multi-branched gold nanoparticles (MBAuNPs) were fabricated using a green chemistry method which employed the reduction of gold ion solute by 2-[4-(2-hydroxyethyl)-1-piperazyl] ethane sulfonic acid. Two types of reporter dyes, indocyanine (IR820 and IR792) and carbocyanine (DTTC [3,3'-diethylthiatricarbocyanine iodide] and DTDC [3,3'-diethylthiadicarbocyanine iodide]), were functionalized to the surface of the MBAuNPs and stabilized with denatured bovine serum albumin, thus forming the surface-enhanced Raman spectroscopy tag. Fluorescein isothiocyanate-conjugated anti-epidermal growth factor receptor to the surface-enhanced Raman spectroscopy tags and the properties of the resulting conjugates were assessed through determination of the Raman signal. Using the MBAuNP Raman probes synthesized in this manner, we demonstrated that MBAuNP provided significantly more surface-enhanced Raman scattering signal when compared with the associated spherical gold nanoparticle of similar size and concentration. MBAuNP enhancements were retained in the surface-enhanced Raman spectroscopy tags complexed to anti-epidermal growth factor receptor, providing evidence that this could be a useful biological probe for enhanced Raman molecular fingerprinting. Furthermore, while utilizing IR820 as a novel reporter dye linked with MBAuNP, superior Raman signal fingerprint results were obtained. Such results provide significant promise for the use of MBAuNP in the detection of numerous diseases for which biologically specific surface markers exist.
authors.affiliation: Department of Chemical Engineering, Northeastern University, Boston, MA, USA.
authors.forename: Jencilin
authors.initials: J
authors.lastname: Johnston
authors.affiliation: Department of Chemical Engineering, Northeastern University, Boston, MA, USA; Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA.
authors.forename: Erik N
authors.initials: EN
authors.lastname: Taylor
authors.affiliation: Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Gilbert
authors.affiliation: Department of Chemical Engineering, Northeastern University, Boston, MA, USA; Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Webster
mesh_terms: D000906:Antibodies / Q000737:chemistry; D052160:Benzothiazoles; D002232:Carbocyanines; D066246:ErbB Receptors / Q000276:immunology; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D055772:Green Chemistry Technology; D007208:Indocyanine Green / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry; D025202:Molecular Diagnostic Techniques / Q000295:instrumentation / Q000379:methods; D015335:Molecular Probes / Q000032:analysis / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000295:instrumentation / Q000379:methods*
chemical_list: D000906:Antibodies; D052160:Benzothiazoles; D002232:Carbocyanines; C541053:IR 820; D015335:Molecular Probes; C025905:3,3'-diethylthiatricarbocyanine; D012710:Serum Albumin, Bovine; D006046:Gold; D066246:ErbB Receptors; D016650:Fluorescein-5-isothiocyanate; D007208:Indocyanine Green
keywords: IR820; SERS; gold nanostars