Poly L- methionine/Electrochemically Reduced Graphene Oxide Composite Film Modified Glassy Carbon Electrode for the Simultaneous Determination of 5-hydroxyindole Acetic Acid and Tyrosine

An effective electrochemical sensor based on poly L- methionine/Electrochemically Reduced Graphene Oxide Composite Film Modified Glassy Carbon Electrode (poly(L-Met)/ERGO/GCE)) has been developed for the individual and simultaneous determination of 5-hydroxyindole acetic acid (5-HIAA) and tyrosine (Tyr). In clinical point of view, simultaneous determination of these analytes is very important and a sensor for the same is not reported yet. This sensor offers sensitive, reproducible and selective determination of 5-HIAA and Tyr. Experimental parameters for the effective determination of the analytes were optimized. Under optimized conditions, quantification of 5-HIAA is possible within the range 1.0 x 10(-5) M to 8.0 x 10(-7) M and for Tyr in two ranges, 1.0 x 10(-5) M to 5.0 x 10(-6) M and 7.0 x 10(-5) M to 2.0 x 10(-5) M. The limit of detection and limit of quantification obtained for 5-HIAA using poly(L-Met)/ERGO/GCE are 5.0 x 10(-7) M and 8.0 x 10(-7) M respectively, and for Tyr, 1.0 x 10(-6) M and 5.0 x 10(-6) M respectively. The sensor was successfully applied for the determination of both 5-HIAA and Tyr in artificial urine and blood serum samples. (C) 2022 The Electrochemical Society (ECS). Published on behalf of ECS by IOP Publishing Limited.

Automated summary

We have developed an electrochemical sensor based on poly L-methionine/electrochemically reduced graphene oxide composite film modified glassy carbon electrode for the simultaneous determination of 5-hydroxyindole acetic acid and tyrosine. The sensor offers sensitive and selective detection, and has been successfully applied to artificial urine and blood serum samples.