Highly Sensitive and Selective Detection of Diabetic Nephropathy Markers by a Perovskite LaNiO_3-xBased Potentiometric Sensor

This work describes the fabrication of efficient biosensors to detect diabetic nephropathy markers (pH, glucose, and creatinine) by constructing a layer-wise sol-gel deposited perovskite LaNiO3-x (LNO) thin-film combined with intermedial annealing (500°C to 700°C). The structural, morphological, and compositional properties of LNO were analyzed by X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. The bilayer-coated LNO thin film annealed at 600°C exhibited the highest pH sensitivity of 65.83 mV pH-1 with 99.36% linearity for pH 2 to pH 12, a minimum hysteresis of 0.6 mV, and an almost unvarying drift rate of 2.04 mV h-1 in an extended gate field effect transistor (EGFET). Furthermore, the optimized film was utilized to detect glucose and creatinine by immobilizing different enzymes on the LNO surface. The glucose sensor was able to detect glucose with a sensitivity of 20.5 mV mM-1, whereas the sensitivity of the creatinine sensor was 126.4 mVpCcreatinine-1 for an acceptable linear range, with high selectivity for their respective target molecules. Hence, an LNO-based EGFET sensor can be considered a decisive solicitant for diagnosing diabetic nephropathy.