Binary Ni-Fe layered double hydroxide on flexible Nickel foam for the wide-range voltammetric detection of fibrinogen in simulated body fluid.

Fibrinogen, a circulating glycoprotein in the blood, is a potential biomarker of various health conditions. This work reports a flexible electrochemical sensor based on Ni-Fe layered double hydroxide (Ni-Fe LDH) coated on Nickel foam (Ni-Fe LDH/NF) to detect fibrinogen in simulated human body fluid (or blood plasma). The nanoflakes like morphology and hexagonal crystal structure of LDH,
synthesized via urea hydrolysis assisted precipitation technique, are revealed by scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD) techniques, respectively. The fabricated sensor exhibits linearity in a wide dynamic range covering the physiological concentration from 1 ng/ml to 10 mg/ml with a sensitivity of 0.0914 mA (ng/ml)-1(cm)-2. This LDH-based sensor is found to have a limit of detection (LOD) of 0.097 ng/ml and a limit of quantification (LOQ) of 0.294 ng/ml (S/N=3.3). The higher selectivity of the sensor towards fibrinogen protein is verified in the presence of various interfering analytes such as dopamine, epinephrine, serotonin, glucose, potassium, chloride, and magnesium ions. The sensor is successful in the trace-level detection of fibrinogen in simulated body fluid with excellent recovery percentages ranging from 99.5% to 102.5%, proving the synergetic combination of 2D Ni-Fe layered double hydroxide and 3D nickel foam as a promising platform for electrochemical sensing that has immense potential in clinical applications.