Biomimetic synthesis of highly biocompatible gold nanoparticles with amino acid-dithiocarbamate as a precursor for SERS imaging

Abstract

Amino acid-dithiocarbamate (amino acid-DTC) was developed as both the reductant and ligand stabilizer for biomimetic synthesis of gold nanoparticles (AuNPs), which served as an excellent surface-enhanced Raman scattering (SERS) contrast nanoprobe for cell imaging. Glycine (Gly), glutamic acid (Glu), and histidine (His) with different isoelectric points were chosen as representative amino acid candidates to synthesize corresponding amino acid-DTC compounds through mixing with carbon disulfide (CS2), respectively. The pyrogenic decomposition of amino acid-DTC initiated the reduction synthesis of AuNPs, and the strong coordinating dithiocarbamate group of amino acid-DTC served as a stabilizer that grafted onto the surface of the AuNPs, which rendered the as-prepared nanoparticles a negative surface charge and high colloidal stability. MTT cell viability assay demonstrated that the biomimetic AuNPs possessed neglectful toxicity to the human hepatoma cell, which guaranteed them good biocompatibility for biomedical application. Meanwhile, the biomimetic AuNPs showed a strong SERS effect with an enhancement factor of 9.8 × 10(5) for the sensing of Rhodamine 6G, and two distinct Raman peaks located at 1363 and 1509 cm(-1) could be clearly observed in the cell-imaging experiments. Therefore, biomimetic AuNPs can be explored as an excellent SERS contrast nanoprobe for biomedical imaging, and the amino acid-DTC mediated synthesis of the AuNPs has a great potential in bio-engineering and biomedical imaging applications.

Therapeutic potential of dithiocarbamate supported gold compounds

“…A strong SERS effect with an enhancement factor of 9.8 Â 10 5 was observed for biomimetic amino acid-DTC AuNPs for the sensing of Rhodamine 6G. 77 This clearly demonstrate that the aptitude biomimetic amino acid-DTC AuNPs can be explored as an excellent SERS contrast nanoprobe for biomedical imaging. The amino acid-DTC mediated synthesis of the AuNPs may also possess great potential in bioengineering and biomedical imaging applications.…”

Polyethyleneglycol nanoparticles adsorbed to glycine as a bioengineered neomaterial for application in inflammatory processes

“…The synthesis of functional materials in nanoscale has been increasing interest in the research, due control mechanisms on material in relation the morphology, size, functionalities and properties [24]. Functional materials such as polymers that are produced on nanometer scale as well as PEG nanoparticles can be used in drug delivery control [25].…”

Hybrid nanomaterial: biocolloidals

“…Figure 1 (Sapsford et al, 2011) shows eight schematic variations of NP-biological structures. The interaction of biomolecules with the NP core can happen in two ways: NPs can Optically coded hybridization probe imaging and delivery Matea et al, 2015;Li et al, 2016;Zhao et al, 2016 Figure 1. Some potential NP-bioconjugate components and multilayer bodies (not to scale): i) biomolecule connecting with NP center; ii) biomolecule connecting with a NP center via interface ligands; iii) biomolecule connecting with NP shell layer that covers the NP center; iv) biomolecule connecting with NP mid shell via interface ligands; v) porous NP center involving capsulated biomolecules; vi) spongy NP center involving capsulated biomolecules covered by a NP shell layer; vii) NP center (or NP center/NP shell bodies) particles are smaller than the biomolecule; viii) NP center (or NP center/NP shell bodies) particles are smaller than the biomolecule connected via interface ligands.…”

“…On the other hand, this encapsulation is also applicable to NPs that are not biocompatible. SiO 2 layers can be polymerized on the surface of those toxic particles to form a shell to generate biocompatible hybrid NPs (Pokhrel et al, 2014;Pla-Roca et al, 2015;Del Mercato et al, 2016;Filip et al, 2016;Li et al, 2016;Piella et al, 2016). Fabrication techniques, such as hybrids, are actually quite hard to achieve by applying silane chemistry, but many SiO 2 NP biohybrids are still synthesized and employed due to their utility (Polavarapu et al, 2014).…”

“…However, there are still challenges encountered during their fabrication, such as purity of biopolymers and batchto-batch reproducibility. Biopolymeric nanomaterials obtained from natural polymers, such as polycarbonates and primary and secondary proteins, have been exploited in various medical applications, such as therapeutic delivery and bioimaging (Lee et al, 2004;Li Y et al, 2011;Li et al, 2016). They can embody various functional moieties for biomodification with natural biosubstrates.…”