Gold nanoparticles for surface-enhanced Raman scattering detection of benzyldimethyldodecylammonium chloride at low concentration.

The oil and gas industry plays a vital role in the global economy. The production process has several critical conditions and can expose metals to corrosion. Surfactants like the quaternary ammonium salt Benzyldimethyldodecylammonium Bromide (BDAC) are currently used to prevent corrosions; classical methods for determining these surfactants have problems in saline samples and usually present high costs. In this context, spectroscopic techniques become an excellent alternative for quaternary ammonium salts detection. Here, a SERS (surface-enhanced Raman scattering) sensor based on gold nanoparticles (AuNPs) synthesized through chemical reduction was used as an alternative method for BDAC detection. We detected BDAC at low concentrations in water solutions: at 5 to 30 ppm (1.47 × 10-5 mol L-1 to 8.82 × 10-5 mol L-1); and had the vibration attempt attribute analyzed. A new study of quaternary ammonium compounds using AuNPs and SERS with a different, easy, and repeatable approach to spectra acquisition is presented and shows to be a promising method applied in quaternary ammonium salt compounds detection for the oil and gas industry.

Balanced Th1/Th2 immune response induced by MSP1a functional motif coupled to multiwalled carbon nanotubes as anti-anaplasmosis vaccine in murine model.

Anaplasmosis is one of the most prevalent tick-borne diseases of cattle caused by Anaplasma marginale. MSP1a surface protein has been shown to be involved in eliciting immunity to infected cattle. Carbon nanotubes (CNTs) has been increasingly highlighted due to their needle like structure, which contain multiple attachment sites for biomolecules and may interact with or cross biological membranes, increasing antigen availability to immune system. Here, we have successfully designed a nanocomplex of a synthetic peptide noncovalently attached to multiwalled CNT (MWCNT). Peptide comprising the core motif of the MSP1a was efficiently adsorb onto the nanoparticle surface. The MWCNT-Am1 nanocomplex exhibited high stability and good dispersibility and in vivo immunization showed high levels of IgG1 and IgG2a, followed by increased expression of pro-inflammatory and anti-inflammatory cytokines. This is a proof-of-concept of a nanovaccine that was able to generate a strong immune response compared to the common antigen-adjuvant vaccine without the nanoparticles.

A carefully designed nanoplatform based on multi walled carbon nanotube wrapped with aptamers.

The interaction between carbon nanotubes (CNTs) and biological molecules of diagnostic and therapeutic interest, as well as the internalization of the CNTs-biomolecules complexes in different types of cell, has been extensively studied due to the potential use of these nanocomplexes as multifunctional nanoplatforms in a great variety of biomedical applications. The effective use of these nanobiotechnologies requires broad multidisciplinary studies of biocompatibility, regarding, for example, the in vitro and in vivo nanotoxicological assays, the capacity to target specific cells and the evaluation of their biomedical potential. However, the first step to be reached is the careful obtainment of the nanoplatform and the understanding of the actual surface composition and structural integrity of the complex system. In this work, we show the detailed construction of a nanoplatform created by the noncovalent interaction between oxidized multi walled carbon nanotubes (MWCNTs) and a DNA aptamer targeting tumor cells. The excess free aptamer was removed by successive washes, revealing the actual surface of the nanocomplex. The MWCNT-aptamer interaction by π-stacking was evidenced and shown to contribute in obtaining a stable nanocomplex compatible with aqueous media having good cell viability. The nucleotide sequence of the aptamer remained intact after the functionalization, allowing its use in further studies of specificity and binding affinity and for the construction of functional nanoplatforms.