Do You Need Gold Nanostars?

Over the past few years, gold nanostars have gained significant relevance in biology and medicine, in particular, in imaging and photothermal therapy, also owing to their biocompatibility. Furthermore, they have improved the sensitivity of diagnostic assays and have been integrated in lab-on-chip platforms for low-cost, field-deployable devices. So, what are gold nanostars?

What are gold nanostars?
Gold Nanostars (GNS) have attracted tremendous attention toward themselves owing to their multi-branched structure and unique properties. These state of the art metallic nanoparticles possess intrinsic features like remarkable optical properties and exceptional physiochemical activities. These star-shaped gold nanoparticles can predominantly be utilized in biosensing, photothermal therapy, imaging, surface-enhanced Raman spectroscopy and target drug delivery applications due to their low toxicity and extraordinary optical features.

How do nanostars work?
Nanostars are synthesized so that they absorb light in the near-infrared region approximately 665±9.7 nm with an average hydrodynamic diameter of 66.3±7.8 nm. The synthesis and characterization by ultraviolet-visible absorption spectroscopy, dynamic light scattering, and transmission electron microscopy have been described previously.

How to synthesize gold nanostars?
Gold nanostars with tunable morphology were synthesized by a seed-mediated growth method using poly(diallyldimethylammonium chloride) (PDDA) as stabilizer. The number and length of the branches of the nanostars can be controlled by adjusting the amount of silver nitrate. In addition, the AuNSs exhibit an excellent catalytic effect toward the reduction of hydrogen peroxide (H2O2) in deoxygenated phosphate buffer (pH 7.0). Thus, the PDDA-protected AuNSs were utilized to modify glassy carbon electrode directly for fabricating non-enzymatic H2O2 sensor. The fast amperometric response, low detection limit, wide linear range, good selectivity and long-term stability for the electrochemical detection of H2O2 imply a good performance of the AuNSs based sensor.

Where gold nanostars can be found?
Gold nanostars have unique optical properties compared to spherical gold nanoparticles of the same core diameter. The spiky uneven surface causes a red shift in the surface plasmon peak and a larger enhancement of the electromagnetic field at the tips of the gold nanostars spikes compared to that of spherical particles. Binding of ligands such as proteins to the gold nanostars surface also causes a larger shift in the surface plasmon resonance peak compared to standard spherical gold nanoparticles. This feature makes them ideal in the development of sensitive SPR-based detection assays. As a global provider of the most comprehensive list of nanoparticles products, CD Bioparticles offers a comprehensive list of functional and conjugated Nanostars, such as SpecNano™ Gold Nanostars, 100 nm(CGS-100) and SpecNano™ Anti-Human IgG (H+L) Conjugated Gold Nanostars, 100 nm(CGSA-Human-100) . At CD Bioparticles, nanostars functionalized with active groups such as NHS, carboxyl, amine and hydroxyl are accessible to all researchers. Conjugated nanostars with a variety of biological ligands are also available for customers' specific requirements.

References
Mousavi, S. M., Zarei, M., Hashemi, S. A., Ramakrishna, S., Chiang, W. H., Lai, C. W., & Gholami, A. (2020). Gold nanostars-diagnosis, bioimaging and biomedical applications. Drug metabolism reviews, 52(2), 299-318.
D’Hollander, A., Mathieu, E., Jans, H., Velde, G. V., Stakenborg, T., Van Dorpe, P., … & Lagae, L. (2016). Development of nanostars as a biocompatible tumor contrast agent: toward in vivo SERS imaging. International journal of nanomedicine, 11, 3703.
Li, Y., Ma, J., & Ma, Z. (2013). Synthesis of gold nanostars with tunable morphology and their electrochemical application for hydrogen peroxide sensing. Electrochimica Acta, 108, 435-440.