Layer-by-layer sensor architecture of polymers and nanoparticles for electrochemical detection of uric acid in human urine samples

Excessive uric acid levels in the human body (hyperuricemia) are the main causes of kidney stones and diabetes. In this study, a layer-by-layer arrangement of polymers and nanocomposites is used as a new electrode sensing material for rapid and direct electrochemical determination of uric acid (UA). The electrode surface architecture was constructed by the incorporation of poly (amidoamine) dendrimer with 0.5 generation (poly (amidoamine) [PAMAM] [D-G0.5]) of multiwalled carbon nanotube-silver nanoparticles (MWCNT-AgNP) and a poly (neutral-red) (poly [NR]) polymer. The PAMAM (D-G0.5)/MWCNT-AgNP/poly (NR)-coated electrode has a good electrocatalytic activity for the determination of UA using cyclic voltammetry and showed remarkable enhancement in current response at a low-oxidation potential (0.3 V). Under optimal conditions, the developed electrochemical sensor showed an excellent and wide linear range for the determination of UA (i.e. 0.016 μM–2500 μM), and the limit of detection was found to be 0.005 μM. The modified sensor system demonstrated excellent sensitivity and selectivity toward the detection of UA in the presence of interfering substances, which are commonly found in urine and human fluid samples. Furthermore, the developed sensor has represented both reproducibility and excellent stability for the UA determination in real samples (human urine).