Silver nanoparticles and magnetic beads with electrochemical measurement as a platform for immunosensing devices.

The simplicity and analytical utility of silver nanoparticles used as immunolabels with screen-printed measurement electrodes is illustrated by demonstrating an appropriate analytical signal for myoglobin (a protein marker for muscle damage) across a range of concentrations of physiological interest for distinguishing potential myocardial infarctions from normal background levels in serum. Silver nanoparticles were used as labels on one of a pair of anti-myoglobin clones while the other clone was covalently attached to magnetic beads. The two clones were selected so as to bind to different sites on the target protein and allow the formation of complexes containing both magnetic beads and silver nanoparticles.

Enhancement by Copper(II) of the voltammetric signal of vitamin B2 applied to its determination in breakfast cereals.

Addition of copper(II) to breakfast cereal samples was shown to significantly enhance the analytical signal obtained by electrochemical reduction of vitamin B(2) using linear sweep voltammetry on disposable carbon electrodes. The enhancement was observed only when dissolved oxygen was present. In model solutions the analytical signal was linear in the concentration range 6-150 ng/mL with a calculated limit of detection of 5 ng/mL (S/N = 3).

Hexacyanoferrate(III) as a mediator in the determination of total iron in potable waters as iron(II)-1,10-phenanthroline at a single-use screen-printed carbon sensor device.

Hexacyanoferrate(III) was used as a mediator in the determination of total iron, as iron(II)-1,10-phenanthroline, at a screen-printed carbon sensor device. Pre-reduction of iron(III) at -0.2V versus Ag/AgCl (1M KCl) in the presence of hexacyanoferrate(II) and 1,10-phenanthroline (pH 3.

Disposable sensor for measurement of vitamin B(2) in nutritional premix, cereal, and milk powder.

Methodologies for the determination of vitamin B(2) in food matrixes and a premix using simple sample conditioning steps coupled with a convenient and cheap electrochemical sensing device are presented. Electrochemical analysis based on differential pulse voltammetry (DPV) coupled to carbon electrodes gave a well-defined reduction peak at -0.42 V versus a Ag/AgCl quasi-reference electrode.