Nickel iron based layered double hydroxides as effective electrochemical sensor towards epicatechin

Tea consumption around the world is increasing day by day as it incorporates energy and refreshment in the human body as a result of polyphenols presence. Among them, epicatechin (EC) is one of the major types of catechins has many potential roles in human health. However, changes in EC level ultimately leads to chronic diseases, hence its detection is essential. In this work, we have fabricated a nickel iron based layered double hydroxides (NiFe-LDH) for the effective detection of EC. LDH are recent attractive materials owing to their hydrotalcite layered structure having many potential applications especially in the area of electrochemistry. XRD, Raman and surface morphology studies confirmed the NiFe-LDH formation and also the primary characterizations revealed the efficient electrochemical behaviour. As a result of the electrostatic attraction between the metal ions and OH of EC, the NiFe-LDH composite exhibited a two wide linear range of 50 nM – 1 µM and 10 µM – 400 µM with detection limit as 9.54 nM and 14.2 µM. Likewise, it exposed 87 % stability in 150 cycles and 3.8 % relative standard deviation in reproducibility. In terms of selectivity the proposed NiFe-LDH needs some improvement as it interacts with quercetin and epigallocatechin gallate. The real time analysis in green tea and black tea unspiked samples showed good recoveries with good linear range. All these results highly recommend the proposed NiFe-LDH as an excellent biosensing platform for device fabrication.