How to fit a response current-concentration curve? Part (Ⅱ): Synergy of heterogeneous PANI@Ni(OH)2/NF towards high performance glucose sensing and a general semi-empirical model

[Display omitted] •Utilized a flow of hydroxylation and polymerization to assemble NEGSs.•Advanced a heterogeneous PANI@Ni(OH)2/NF NEGS without any conductive adhesive.•PANI@Ni(OH)2/NF showed a high sensitivity in a wide glucose concentration range.•Set up a general semi-empirical model of current-concentration suitable for NEGSs.•The nonlinear i – c model significantly reduced errors caused by linear fitting. Herein a heterogeneous material PANI@Ni(OH)2/NF, hydroxylated nickel foam (NF) modified by polyaniline (PANI), was assembled via an easy-to-operate sequential method. The hydroxylation obviously improves the reaction rate from Ni(II) to Ni (III) and the modification notably decreases the interface resistance. Benefitting from the synergy of Ni(OH)2, NF, and PANI, by means of three-segment linear fitting, PANI@Ni(OH)2/NF shows a high sensitivity up to 2248.7 μA mM cm−2, a low detection limit of 0.52 μM, and excellent selectivity for glucose sensing when the glucose concentration (cR*) is from 0.001 mM to 16.000 mM. Further, we deduced a general semi-empirical model to describe the relationship between current i(cR*) and cR*, which eliminated the errors near the junction of two adjacent lines obviously and boarded the detection range. By comparing with the multi-segment linear fitting and our previous formula, both the mean d-value of 0.164 mA and the SD of 0.0218 mA obtained from the model are the lowest, respectively. A similar comparison was carried out in literature data, and the results are also satisfactory.