Study of the Nonenzymatic CZO Lactic Acid Sensor Modified by Graphitic Carbon Nitride and Iron-Platinum Nanoparticles

This study proposed a nonenzymatic sensor for lactic acid detection based on copper doped zinc oxide (CZO) modified by graphitic carbon nitride (g-C 3 N 4 ) and iron-platinum nanoparticles (FePt NPs). The silver paste electrodes of the sensor were prepared using screen printing technology, and the CZO sensing film was deposited using radio frequency (R.F.) sputtering system. The g-C 3 N 4 nanosheet solution was prepared through liquid exfoliating of the g-C 3 N 4 in water. The sensing film was modified by adding different contents of the FePt NPs in g-C 3 N 4 solution. The various concentrations of the FePt NPs were 0.03, 0.1, and 0.3 wt%. The {V} - {T} measurement system was applied to investigate the sensing characteristics of the lactic acid sensors based on CZO sensing film modified by g-C 3 N 4 and FePt NPs. The surface morphology of the sensor was analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD), and dynamic light scattering (DLS). In this work, the 0.1 wt% FePt NPs-g-C 3 N 4 lactic acid sensor has the best sensitivity, linearity, response time, and the limit of detection (LOD).