Total analysis of endocrine disruptors in a microchip with gold nanoparticles

The development of a simple, sensitive, and direct method for the total analysis of certain endocrine disruptors was performed by integrating preconcentration steps to a separation step on a microchip through the modification of the field-amplified sample stacking and field-amplified sample injection steps. To improve the preconcentration and separation performances, the preconcentration and separation buffers were modified with citrate-stabilized gold nanoparticles (AuNPs). For the detection of the separated samples, cellulose-dsDNA/AuNPs-modified carbon paste electrodes were used at the channel end. The experimental parameters affecting the analytical performances, such as the buffer concentration, water plug length, SDS concentration in the separation buffer, AuNPs concentration, preconcentration time, detection potential and electrode to channel distance, were examined. The detection limits of the test compounds were between 7.1 and 11.1 fM and that for 4-pentylphenol was 7.1 (±1.1) fM. Dynamic ranges were in the range from 0.15 to 600.0 pM. The experiments with real samples were performed to evaluate the reliability of the proposed method.