Selective determination of monosodium glutamate (Ajinomoto) in food samples using a potentiometric method with a modified multiwalled carbon nanotube based molecularly imprinted polymer

The aim of the present work was to test the use of a surface modified multi-walled carbon nanotube based molecularly imprinted polymer (MWCNT-MIP) for the selective identification of monosodium glutamate (MSG) in food samples. The hydroxylated MWCNTs were reacted with allyl bromide to form vinylated MWCNTs (MWCNT-CH=CH2). The MWCNT-MIP was synthesized by selective polymerization of MWCNT-CH=CH2 with itaconic acid (IA) as the functional monomer in the presence of MSG using ethylene glycol dimethacrylate (EGDMA) as a cross-linker and alpha,alpha'-azobisisobutyronitrile (AIBN) as the initiator. The organized material was characterized using different instrumental techniques. The proposed sensor has a response time of similar to 1 min and the calculated detection limit for MSG was 1.0 x 10(-9) mol L-1. The sensitivity obtained for the MWCNT-MIP sensor is 56 mV per decade. The linear range obtained for the sensor is 10(-9) to 10(-5) mol L-1. The MWCNT-MIP sensor membrane is an effective tool for the identification of MSG in food samples.