The third generation (G‐3) polypropylenimine hexadecaamine dendrimer (DAB‐Am‐16) was grafted onto the silica gel surface. The modified silica interacts easily with Cu2+ and then with potassium ferrocyanide to form copper hexacyanoferrate. The modified silica was characterized by the following techniques: Nuclear Magnetic Resonance (NMR), FTIR spectroscopy, Energy Dispersive X‐ray (EDX) and Cyclic Voltammetry. The modified silica containing copper hexacyanoferrate (CuHCFSD) was tested for a voltammetric determination of nitrite using a modified graphite paste electrode.

Poly(propylene)imine hexadecylamine dendrimer (DAB-Am-16) was anchored on the surface of 3-chloropropylsilyl silica gel and subsequently interacted with copper nitroprusside. The composite was characterized by infrared (FTIR), energy dispersive X-ray (EDX), and cyclic voltammetry. The above techniques confirmed the successful anchoring of the dendrimer on the silica gel modified surface and its interaction with copper nitroprusside. The cyclic voltammogram of CuNPSD was found to exhibit two redox couples with (Eθ′)1= 0.30 V and (Eθ′)2= 0.78 V versus Ag/AgCl ( mol L−1;  mV s−1) attributed to the redox processes and , respectively. The CuNPSD-modified graphite paste electrode was found to show a linear response of to  mol L−1for nitrite determination with a detection limit (DL) of  mol L−1and an amperometric sensitivity of 25.0 mA/mol L−1. The CuNPSD-modified graphite paste electrode was found to show a good electrochemical stability and an excellent response to the electrocatalytic oxidation of sodium nitrite.

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