Carbon Paste Electrode Modified Poly-Glutamic Acid (PGA) with Molecularly Imprinted for Detection of Rhodamine B

TL;DR

This study developed a molecularly imprinted carbon paste electrode modified with poly-glutamic acid for selective potentiometric detection of Rhodamine B, demonstrating good sensitivity, accuracy, and comparability with UV-Vis methods.

Contribution

A novel molecularly imprinted electrode using poly-glutamic acid was created for Rhodamine B detection, offering a new electrochemical sensing approach.

Findings

Detection limit of 8.91 x 10^-6 M for Rhodamine B

Measurement range from 10^-5 M to 10^-2 M

Comparable accuracy to UV-Vis spectrophotometry

Abstract

Rhodamine B is a synthetic dye used for coloring textiles, paper and ceramics. In addition, Rhodamine B is also often used for coloring ingredients in food ingredients such as crackers, syrups, candy, cakes, and is often used for coloring lipsticks. The accumulation of Rhodamine B in the body can cause liver, kidney and lymph damage. In this study, a modified carbon paste electrode (CPE) with molecularly imprinted polymers (glutamic acid) was developed for the determination of rhodamine B using potentiometric techniques. The modification was carried out by electropolymerization of glutamic acid monomer from a solution containing 3.0 mM glutamic acid and 1.0 mM rhodamine B in a phosphate buffer pH 7 using a cyclic voltammetry technique of 15 cycles in the potential range between (-0.2 V) to (1.8 V) with a scan rate of 100 mV/sec. Measurements with these electrodes have optimum performance at pH 4. The Nerst factor is 29.2 mV/decade. The measurement range is 10-5 M to 10-2 M. With the detection limit of Rhodamine B which can be measured by the electrode is 8.91 x 10-6 M. This electrode has a fairly good value of accuracy and precision, and does not have a significant difference. when compared with the UV-Vis spectrophotometric method.