Preparation of Aminodextran−CdS Nanoparticle Complexes and Biologically Active Antibody−Aminodextran−CdS Nanoparticle Conjugates

Abstract

Stable aqueous dispersions consisting of CdS nanoparticles having modal diameters, ranging between 2 and 8 nm, were prepared with amino-derivatized polysaccharides (aminodextrans, hence abbreviated as Amdex) as the stabilizing agents. The size, stability, and luminescence intensity of such dispersions were shown to be dependent on the types of the cadmium salts and aminodextrans used, as well as on the reactant concentrations. Specifically, it was demonstrated that the degree of substitution of amino groups in the aminodextran molecules greatly affected the properties of the dispersions; i.e., with higher degree of substitution, smaller CdS particles and higher luminescence intensity were achieved. It was also shown that the Amdex-CdS nanoparticle complexes could be activated and conjugated with antibody by conventional means. Molecular weight ranges of the Amdex and their complexes with CdS nanoparticles and the purity of antibody-Amdex-CdS nanoparticle conjugates were determined by polyacrylamide gel electrophoresis combined with Coomassie blue staining of resultant gel bands. The purified conjugate of the aminodextran-CdS nanoparticle complex with anti-CD4 monoclonal antibody was mixed with a whole blood control, followed by indirect sheep antimouse antibody-phycoerythrin (SAM-PE) labeling of washed cells incubated with T4-5X-Amdex-CdS. Red blood cells were then lysed and quenched, and the resulting mixture, which was run on a flow cytometer with 488.0 nm argon ion laser excitation, suggested that the T4 antibody from the conjugate was present specifically on lymphocytes.

Multi-step synthesis of nanoparticles performed on millisecond time scale in a microfluidic droplet-based system

“…39 Alternatively, turbulence-based mixing of various solvents with supercritical fluid enhanced by an ultrasound field has been used to precipitate protein, 40 and drug, 41 nanoparticles of controlled size and distribution. Continuous flow microfluidic methods for synthesis of nanoparticles have also appeared in literature.…”

Engineering of poly(ethylene glycol) chain-tethered surfaces to obtain high-performance bionanoparticles

“…Since the use of ligand-conjugated QDs as fluorescent biolabeling reagents was reported in 1998 by the groups of Alivisatos [51] and Nie [52], many approaches to QD applications have been realized in the bioanalytical field such as DNA sequencing, tissue immune-diagnostics and single molecular imaging [53][54][55][56][57][58][59][60][61][62][63][64][65][66]. The advantages of QDs as biolabeling agents are (i) tunability of the emission wavelength by changing the particle size, (ii) a sharp and symmetrical emission peak, (iii) the high intensity and long lifetime of the fluorescence and (iv) a wide range of excitation wavelengths.…”

Synthesis, Characterization and Antibacterial Study of Copper Oxide-Graphene Nanocomposites

“…There is a need to develop more safe and cost-effective biocidal materials. Nanosized particles either simple or composite by nature, exhibit unique physical and chemical properties and shows a potential of being used in various biomedical applications [7,8].Studies on graphene and graphene-based materials has found their use in medicine and life sciences which includes imaging [9], biosensors [10,11], drug delivery [12][13][14] and pathogen control [15,16]. The response of using graphene oxide on microorganisms has been studied extensively.…”