NiAl Layered Double Hydroxides and PdNiO as Multifunctional Anodes for Prospective Self‐Powered Lab‐on‐a‐Chip Dopamine Sensors.

Abstract: The purpose of this work is the evaluation of two bimetallic materials, PdNiO and NiAl‐layered double hydroxides (NiAl‐LDHs) for their prospective use in Lab‐on‐a‐Chip devices, in which urea contained in human urine is used as fuel to provide the energy required by the device and dopamine in the sample is detected. A urea microfluidic fuel cell, using human urine as fuel and NiAl‐LDHs and PdNiO as anodes, was constructed and evaluated, resulting in a cell potential of 1 V with 50.19 mW/cm² power density for NiAl‐LDHs and 0.9 V and 32.94 mW/cm² for PdNiO. The multifunctionality of these anodes was extended for detecting dopamine with detection limits of 7.38×10⁻⁸ M and 5.46×10⁻⁶ M for NiAl‐LDHs and PdNiO, respectively. The higher content of hydroxides on NiAl‐LDHs than PdNiO material allowed a better activity for urea oxidation and dopamine detection. These results show the prospects for self‐powered biomedical Lab‐on‐a‐Chip device development. [ABSTRACT FROM AUTHOR]