Optimizing the sensing performance of amperometric creatinine detection based on creatinine deiminase/Nafion®-nanostructured polyaniline composite film by mixture design method

Nafion®-nanostructured polyaniline (nsPANi) composite film is prepared using cyclic voltammetry (CV) and immobilized with creatinine deiminase (CD) enzyme and is used to sense creatinine in a buffer phosphate solution. The conditions for preparing Nafion®-nsPANi composite film are optimized by using a mixture design for which the sensitivity is the response. The relationship between the sensitivity of the amperometric creatinine biosensor (y) and the normalized aniline concentration (Y₁), HCl concentration (Y₂) and scanning rate (Y₃) is y = 119.44Y₁ + 45.23Y₂ + 100.93Y₃ + 255.69Y₁Y₂ + 313.16Y₁Y₃ + 430.56Y₁Y₂Y₃

The maximum sensitivity of an amperometric creatinine biosensor that is constructed using Nafion®-nsPANi composite film in 0.0943 M aniline, 0.9024 M HCl and using a scanning rate of 27.88 mV s ^− 1 is 2013.2 μA mM⁻¹ cm⁻², which is 54.9% better than the sensitivity of a conventional experimental technique. The amperometric creatinine biosensor is 6.60% less sensitive after sensing 0.15 mM creatinine 240 times. The amperometric creatinine biosensor incurs insignificant interference in 0.138 mM urea, 0.085 mM ascorbic acid (AA) and 5.54 mM glucose.