Cryogelation of Chitosan Using Noble-Metal Ions: In Situ Formation of Nanoparticles

One of the purposes of the project was to develop the method of preparation of 3D macroporous hydrogel with a structure of interconnected pores by the use of noncovalent interactions. The combination of chitosan and noble-metal complexes was investigated as cross-linking agents for the preparation of ionic cryogels (ICs). Furthermore, the treatment of the ICs containing gold complex by glutaraldehyde results in spontaneous formation of gold nanoparticles (AuNPs) and chemical cross-linking of the cryogel. The characterization of prepared macroporous materials was carried out by the use of FTIR, SEM, TEM techniques, and texture analyzer. A new strategy for control of size distribution of AuNPs was suggested. The size distribution of obtained AuNPs and their population inside of walls of cryogels was estimated. A method for quantifying unreacted chloroauric acid in the presence of acetic acid was proposed. The possibility of use of prepared cryogels with immobilized AuNPs as a catalytic flow through reactor is shown

RoxP detection on skin <i>in vivo</i>.

<p>(A) RoxP detection with the RoxP-MIP capacitive biosensor for a RoxP spiked sample containing the same buffer composition as skin swabs, (B) or from non-spiked samples (control sample; orange) or skin swabs (blue) using a dilution ratio of 1/10. A running buffer of 50 mM Tris pH 7.4, and a regeneration buffer of 25 mM glycine-HCl pH 2.5 supplemented with 0.05 M Tween-20 was used, operating the instrument at a speed of 100 μl/min and a sample volume of 250 μl.</p

SEM micrographs of RoxP imprinted capacitive gold electrodes.

<p>(A) Bare gold electrode, and (B-D) RoxP-imprinted electrodes in different magnifications (B: 1,000x; C: 1,500x; D: 2,500x).</p

Selectivity coefficients of RoxP-MIP capacitive biosensor.

<p>Selectivity coefficients of RoxP-MIP capacitive biosensor.</p

Binding of RoxP to a MIP-electrode.

<p>(A) Actual sensorgram showing real-time binding of RoxP to the RoxP-imprinted gold electrode indicating i) a stable baseline with the RoxP-electrode having template-specific cavities (white star), ii) injection of sample, and iii) binding of RoxP to the electrode, resulting in a change in capacitance. (B) Using different concentrations of RoxP, a calibration curve was established and fitted to a linear regression model. A running buffer of 50 mM Tris pH 7.4, and a regeneration buffer of 25 mM glycine-HCl pH 2.5 supplemented with 0.05 M Tween-20 was used, operating the instrument at a speed of 100 μl/min and a sample volume of 250 μl.</p